Bump the python-dependencies group with 3 updates

Bumps the python-dependencies group with 3 updates: [coverage](https://github.com/nedbat/coveragepy), [tox](https://github.com/tox-dev/tox) and [mypy](https://github.com/python/mypy).


Updates `coverage` from 7.6.3 to 7.6.4
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@7.6.3...7.6.4)

Updates `tox` from 4.21.2 to 4.23.0
- [Release notes](https://github.com/tox-dev/tox/releases)
- [Changelog](https://github.com/tox-dev/tox/blob/main/docs/changelog.rst)
- [Commits](tox-dev/tox@4.21.2...4.23.0)

Updates `mypy` from 1.11.2 to 1.12.1
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.11.2...v1.12.1)

---
updated-dependencies:
- dependency-name: coverage
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: python-dependencies
- dependency-name: tox
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: python-dependencies
- dependency-name: mypy
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: python-dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>