Publish automatically to PyPI

[aaron-skydio]

Use the pypa-blessed github action to publish built wheels automatically
to PyPI:
https://packaging.python.org/en/latest/guides/publishing-package-distribution-releases-using-github-actions-ci-cd-workflows/

Just following the instructions there, with modifications to handle our
three different packages.

This setup is much nicer in combination with automatic versioning; on
each push to main we publish a dev release to TestPYPI, and when a tag
is pushed (which will tell setuptools_scm that the symforce version
should be that tag), wheels are published to PyPI.

Topic: sf-auto-publish
Relative: sf-auto-version

[aaron-skydio]

Reviews in this chain:
└#417 Use setuptools_scm for versioning
　└#418 Publish automatically to PyPI

[aaron-skydio]

#	head	base	diff	date	summary
0	8bf3a3de	7dffc872	diff	Jan 3 11:35 AM	2 files changed, 59 insertions(+), 6 deletions(-)
1	deb7a960	bce9c44a	rebase	Jan 3 12:22 PM	0 files changed
2	121ffd65	2a5d6a28	rebase	Jan 3 12:52 PM	0 files changed