Bumps [sigstore/gh-action-sigstore-python](https://github.com/sigstore/gh-action-sigstore-python) from 2.1.1 to 3.0.0.
- [Release notes](https://github.com/sigstore/gh-action-sigstore-python/releases)
- [Changelog](https://github.com/sigstore/gh-action-sigstore-python/blob/main/CHANGELOG.md)
- [Commits](sigstore/gh-action-sigstore-python@61f6a50...f514d46)

---
updated-dependencies:
- dependency-name: sigstore/gh-action-sigstore-python
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Signed-off-by: Nathan Weinberg <nweinber@redhat.com>