Drop outdated Appveyor build status badge from README

Oh right GHA insists on single-quoted strings

I said, drop Appveyor

Drop Appveyor, add Windows builds to GHA

Add Python 3.14, drop 3.8 and 3.9

Drop Python 3.7 support

Fix logic error in get_leaking_objects(objects)

GitHub Actions badge URLs changed

I have to run gh release create _after_ pushing the new tag!

Back to development: 3.6.3

Preparing release 3.6.2

Merge pull request #81 from mgedmin/py313

Add Python 3.13 support

f_locals labeling doesn't work since Python 3.7

Update release.mk