This is instead of the commit we reverted in the previous commit.
The problem is that django keeps the connection per thread and it relies
on django itself to clean them up before/after connections.
We can't do this, because django is unaware of fastapi, so we have to
manage this ourselves.
The easiest way is to call it at the beginning of evenry route and every dep.
We need to do it for each because unfortunately fastapi may send them to
different worker threads.
