Bump importlib-metadata from 1.7.0 to 7.1.0 in /docker/pyotrs

Bumps [importlib-metadata](https://github.com/python/importlib_metadata) from 1.7.0 to 7.1.0.
- [Release notes](https://github.com/python/importlib_metadata/releases)
- [Changelog](https://github.com/python/importlib_metadata/blob/main/NEWS.rst)
- [Commits](python/importlib_metadata@v1.7.0...v7.1.0)

---
updated-dependencies:
- dependency-name: importlib-metadata
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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