Forwarded request #1055981 from bnavigator

- Remove flit from build requirements: The real used backend
is hatchling
- Clean up specfile
* remove duplicate copyright header
* remove catchall in files section
- Drop python-fastapi-disable-broken-tests.patch
- Prune the test suite when run in lettered staging projects:
python-mocket pulls this into Ring1. Let's make it as painless as
possible.