"Fake it until you make it"…?
Well, not exactly like @keshlam's saying that you have it made when you can fake sincerity.
Take notes for yourself.
makes you look interested
might actually lead to you becoming interested or learning something
Perhaps provide evidence of the amount of time wasted. Although whether you want to share that with your boss is a different issue. Perhaps useful to you when you become a boss, or if you get a better boss.
Overall: group meetings are sometimes more efficient for the company, even if many or most of the participants are bored for most of the meeting. an accidental connection between two people who did not know they should be talking to each other might save the company many weeks of work and millions of dollars.
But of course it's a question of trade-off. Your notes might provide quantifiable evidence.
Finally: looking or acting visibly bored is insulting. That in itself can be career limiting for you.
---+ DETAIL (TL;DR)
---++ take notes
Something I do when I am less interested in a topic is take notes. Imagine that I was writing the minutes for such a meeting. More importantly, don't imagine but actually do take notes for yourself. Over time you might find yourself becoming interested, or possibly just learn something that might help you if you are in the position of your boss.
IIRC this technique is recommended by several "personal productivity" guru types. IIRC has also been recommend that people like your boss, managers or team leaders, or just informal leaders, use "please take minutes" or less onerous "I would appreciate it if you could send me some notes after the meeting" (which doesn't mean that they have to be quite complete as minutes) as a way of getting people like you who are not so actively involved, well, involved.
Why minutes or notes? If the meeting itself is a waste of time, isn't taking minutes or notes even more of a waste of time, especially if you have to spend five or 10 minutes after the meeting to organize them? Well, yes: but I believe it was Andy Grove, famous for managing Intel during its period of growth, who said something like "if it is not worth taking minutes, then it's not worth having the meeting". Plus, the ability to efficiently take minutes or notes in meetings will definitely in itself be useful at other points in your career. "Efficiently" meaning taking the minutes or notes, but not spending too much time on them.
If it is the case that you are having too many meetings, wasting time not just for yourself but also for other people, then your notes are evidence. Especially if you have time spent on them, e.g. half an hour talking about code indentation rules - people know how to use indentation programs or editors? Perhaps your boss would not be interested in such feedback, but some are, especially if documented well as opposed to inchoate whining it's such a waste of time".
Also, in such team wide communications meetings, you might be lucky to get only 10 or 15 minutes worth of discussion relevant to you out of an hour long meeting. Heck, you might only get one really important action item more piece of information over months of such meetings. But if that important piece of information saves you or somebody else many hours or days of work, then the meetings will be worthwhile. Your notes may show you that sort of thing is happening. Or not.
---++ meetings versus technology
Why big group meetings and not 1:1 meetings email or Slack or… ?
Partly it is the efficiency trade-off for broadcast or multitask versus point to point communication: while 8 of 10 people might be wasting an hour once a week, one benefiting, the person providing the useful information might have to spend, say, 10 hours if they were going to have 1:1 meetings or emails to everybody who might possibly be involved.
Why not group emails? Well, evidence is that group emails are often less efficient than meetings, because they take small amounts of time for each email assuming you are not getting involved in writing long replies) over a long time period, and interrupt people who are bored equally by in person group meetings or group emails.
Yes, filtering… Most people don't know how to write email filters. Most email programs don't make writing good email filters efficient or maintainable. (I put both Gmail and Outlook in those classes.) perhaps one day we will all have ChatGPT like personal assistants that will do a better job of determining what you need to look at in your email then gmail begin "important" classifications. Heck, perhaps someday AI personal assistants will help provide some of the synergistic interconnections that group meetings do, with less overhead. But I don't think we're there yet. (I would love to hear from people who may be paying for subscriptions to systems like ChatGPT, and are using it not just for queries, but for such background monitoring of communications like email. But if that's going to replace group meetings, then we're going to need a lot more group broadcast email, which are proven inefficient when you don't have good filters.)
Why not Slack, or forums such as stack exchange where people can go looking for the stuff they're interested in? Well, sometimes the stuff you need to know is not what you naturally go looking for.
Overall groups of people who are working or living together need some communication that is broadcast or "forced" upon all members. Opportunity for synergy, opportunity for connecting group members who do not know about each other's interest.
It's a question of time efficiency: we need a certain amount of such "forced" "group" "multi" communication, to get a certain amount of communication and cooperation between people who don't know they should be talking to each other. But not so much that too much time is wasted.
An hour a week, probably OK.
A four hour meeting a month, may be OK.
A four hour meeting every day, definitely not.
Note: "agile" development methodologies often have a "stand up meeting" 10 minutes or so every day. Depending on the agile guru, perhaps as long as as half an hour although that seems a bit long to me. "Stand up", literally standing up, so people do not get comfortable sitting in chairs.
More about technological alternatives to group meetings, like email or Slack or forums like stack exchange…
I'm a big advocate of such. But management study results show that none of them are home runs in and off themselves. Sometimes for particular communities (e.g. my first employer was an pioneer, and we used UIUC notes files and later news groups very well). But even in that community we had people reluctant to participate, or unfamiliar. Yes, they might've been Old fogeys or tech writers, but they were still important. Some companies have the luxury of being able to say "we should not hire anybody who cannot use Slack". But that can dramatically reduce your hiring pool. (Plus, don't get me going about how slack lead to wasted time.)
Meetings are lowest common denominator. Almost everybody can handle meetings. (not quite everybody, e.g. I have some deaf friends who have difficulty participating in meetings.)
If you can invent or develop a technological alternative that accomplishes as much as in person meetings do, well you might have a good product. If you don't want to code it up, or if you think that it is already been created, well, you might try persuading the old fogies. Your meeting notes might provide evidence.
---++ don't piss off other people
Also remember: being visibly bored can be disrespectful and insulting to other members of the meeting. That can be decidedly career limiting. It's just not nice.