F37: remove Sphinx version lower bound

Update to 0.28.0 (close RHBZ#2221008)

Conditionalize the uvloop test dependency

Run tests with/without PYTHONASYNCIODEBUG=1 and uvloop
This follows the “test” target of the upstream Makefile

Ensure README.rst is packaged

Use new (rpm 4.17.1+) bcond style

Remove explicit %set_build_flags, not needed since F36

Don’t assume %_smp_mflags is -j%_smp_build_ncpus

Drop %%pyproject_build_lib (F37+)

Update to 0.27.0 (close RHBZ#2138024)

Drop test skip for upstream issue #877
The problem was in a GCC 12 pre-release, and was resolved by GCC 12 final

Update License to SPDX

Rebuilt for https://fedoraproject.org/wiki/Fedora_37_Mass_Rebuild

Update to 0.26.0 (close RHBZ#2105049)

Rebuilt for Python 3.11

Rebuilt for https://fedoraproject.org/wiki/Fedora_36_Mass_Rebuild