Deps: Bump the python-packages group across 1 directory with 3 updates

Bumps the python-packages group with 3 updates in the / directory: [coverage](https://github.com/nedbat/coveragepy), [httpx](https://github.com/encode/httpx) and [tomli](https://github.com/hukkin/tomli).


Updates `coverage` from 7.6.7 to 7.6.8
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@7.6.7...7.6.8)

Updates `httpx` from 0.27.2 to 0.28.0
- [Release notes](https://github.com/encode/httpx/releases)
- [Changelog](https://github.com/encode/httpx/blob/master/CHANGELOG.md)
- [Commits](encode/httpx@0.27.2...0.28.0)

Updates `tomli` from 2.1.0 to 2.2.1
- [Changelog](https://github.com/hukkin/tomli/blob/master/CHANGELOG.md)
- [Commits](hukkin/tomli@2.1.0...2.2.1)

---
updated-dependencies:
- dependency-name: coverage
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: python-packages
- dependency-name: httpx
  dependency-type: indirect
  update-type: version-update:semver-minor
  dependency-group: python-packages
- dependency-name: tomli
  dependency-type: indirect
  update-type: version-update:semver-minor
  dependency-group: python-packages
...

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