chore(deps): bump sigstore/cosign-installer from 3.7.0 to 3.8.0 (#4411)

Bumps [sigstore/cosign-installer](https://github.com/sigstore/cosign-installer) from 3.7.0 to 3.8.0.
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](https://github.com/sigstore/cosign-installer/compare/dc72c7d5c4d10cd6bcb8cf6e3fd625a9e5e537da...c56c2d3e59e4281cc41dea2217323ba5694b171e)

---
updated-dependencies:
- dependency-name: sigstore/cosign-installer
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

.github/workflows/helm.yml

@@ -125,7 +125,7 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Install cosign
-        uses: sigstore/cosign-installer@dc72c7d5c4d10cd6bcb8cf6e3fd625a9e5e537da # v3.7.0
+        uses: sigstore/cosign-installer@c56c2d3e59e4281cc41dea2217323ba5694b171e # v3.8.0
         with:
           cosign-release: 'v2.4.1'