Bump sigstore/gh-action-sigstore-python from 3.0.1 to 3.1.0

Bumps [sigstore/gh-action-sigstore-python](https://github.com/sigstore/gh-action-sigstore-python) from 3.0.1 to 3.1.0.
- [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](https://github.com/sigstore/gh-action-sigstore-python/compare/v3.0.1...v3.1.0

)

---
updated-dependencies:
- dependency-name: sigstore/gh-action-sigstore-python
  dependency-version: 3.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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