Bump sigstore from 2.3.0 to 2.3.1 (#1146)

Bumps [sigstore](https://github.com/sigstore/sigstore-js) from 2.3.0 to 2.3.1.
- [Release notes](https://github.com/sigstore/sigstore-js/releases)
- [Commits](https://github.com/sigstore/sigstore-js/compare/[email protected]@2.3.1)

---
updated-dependencies:
- dependency-name: sigstore
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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