GitHub Actions: Enable python-version: 3.5

[cclauss]

No description provided.

[ryzokuken]

Great, thanks! I'd try to squash and merge to avoid the merge commits creeping into master.

[ryzokuken]

(P.S. 3.5 still fails?)

[targos]

Error:

>     self.assertEqual(expected_msbuild_settings, actual_msbuild_settings)
E     AssertionError: {'ResourceCompile': {'AdditionalOptions': '[6986 chars] ''}} != {'': {'GenerateManifest': 'true', 'IgnoreIm[6983 chars] ''}}
E     Diff is 9880 characters long. Set self.maxDiff to None to see it.

pylib/gyp/MSVSSettings_test.py:1091: AssertionError
=========================== short test summary info ============================
FAILED pylib/gyp/MSVSSettings_test.py::TestSequenceFunctions::testConvertToMSBuildSettings_actual
FAILED pylib/gyp/MSVSSettings_test.py::TestSequenceFunctions::testConvertToMSBuildSettings_full_synthetic

[cclauss]

Python 3.5 is end of life.