Currently I am working in a small team of six developers. Colleagues are often having short talks and flashbacks related to extra work activity (work related decisions they made while not at work), which involves partying, clubbing and bar crawling. For example, they decided to replace/remove a large part of the codebase because it had problem that I fixed (they didn't know that I worked on the code all, and were surprised, we don't use version control but that's separate issue), and indirectly excluded me from the decision making process.
They usually go together after the end of the work day, and on Friday even earlier if boss gives permission. I have a feeling that I am excluded and miss out team bonding and project related decision making process, and also suspect that age gap is the reason I'm not invited. I am 28 years old while second oldest team member is 22.
Overall problem is that I feel excluded from work process in very age specific way: colleagues are going to places with an age ceiling and conducting decision making there is the most obvious example. Colleagues also do not use social media I know of (Facebook, Slack, WhatsApp, LinkedIn) or mail for work stuff.
They are explicitly greenlit by management, and they indeed are more productive this way. Problem is that I am left out, and I can't change job easily, I have been consistently sending CVs around but at my age it is incredibly hard to find work in the software industry. The fact that I can't speak local language further decreases my prospect pool.
How can I handle this situation professionally?