ci: Don't automatically publish wheels for pre-releases, disable 32-bit windows wheels.

[MarquessV]

This stops wheels from publishing on pre-releases automatically. A pre-release will still always be created on merge to main, but only a sdist will be published to PyPI. The Publish workflow can be triggered manually with the publishWheels option if we decide we want to create wheels for a particular pre-release.

I validated these changes as best as I could with nektos/act:

A new pre-release being published only results in a sdist being published

act release -n -e .github/test_events/python_prerelease.json -W .github/workflows/release-python.yml

A manual run by default only publishes a sdist

act workflow_dispatch -n -W .github/workflows/release-python.yml

A full release being published results in a sdist and wheels being published

act release -n -e .github/test_events/python_release.json -W .github/workflows/release-python.yml

A manual run with publishWheels set to true publishes a sdist and wheels

act workflow_dispatch -n --input publishWheels=true -W .github/workflows/release-python.yml