Set up automated publish workflow, trusted publishing, pyproject.toml

[Mr0grog]

Now that EDGI’s web monitoring project is spinning back up again, it would be good to smooth out the release process here by automating and modernizing it a bit.

We did something similar with Wayback last year; relevant PRs:

• Try replacing setup.* with pyproject.toml wayback#144
• Use hatch, hatch-vcs; drop setuptools, versioneer. wayback#145
• Follow best practice of a src/ subdir. wayback#154
• Do PyPI release in GHA wayback#155
• Fix _version.py path in gitignore file wayback#156
• Remove ref-names field from git_archival.txt wayback#162

There are probably more critical things in the pipe to get done first, though, e.g. #145 and the whole mess around cchardet leaving us stuck on Python <= 3.10.

[Mr0grog]

Relatedly… when I published v0.1.5, PyPI sent me a warning:

your recent upload of 'web-monitoring-diff-0.1.5.tar.gz' is incompatible with PEP 625 because it does not contain the normalized project name 'web_monitoring_diff'.

In most cases, this can be resolved by upgrading the version of your build tooling to a later version that supports PEP 625 and produces compliant filenames.

More reasons for build modernization.