You quit your job and are on vacation the whole last month of your employment period. What would happen, if you start a new job in this month, besides to earning two wages?
This seems kind of unethical, but from my point of view there is no damage to any involved parties (You, your current employer, your future employer, the government). Is there anything that forbids this practice? Who could find out, that you have two jobs simultaneously and how would they try to punish you?
Aside from the ethical problem, this is a legal problem as well!
You would have 2 jobs at the same time (Zweitjob) and have to declare it at your new employer. Many companies forbid having a second job in the employment contract. One of your 2 employers would have to declare themselves as the second job (Zweitjob) at the social insurance to make sure you pay the right amount of taxes. Good luck getting your old company to do so.
Not declaring both jobs is illegal and might result in high penalty payments (that YOU have to pay). It might also be a reason for termination without notice if you don't inform your new employer about the second job and they figure it out eventually.
