Bump sigstore/gh-action-sigstore-python from 2.1.1 to 3.0.0 (#986)

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@v2.1.1...v3.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci-cd.yml

@@ -461,7 +461,7 @@ jobs:
       uses: pypa/gh-action-pypi-publish@release/v1
 
     - name: Sign the dists with Sigstore
-      uses: sigstore/gh-action-sigstore-python@v2.1.1
+      uses: sigstore/gh-action-sigstore-python@v3.0.0
       with:
         inputs: >-
           ./dist/${{ needs.build-pure-python-dists.outputs.sdist-filename }}