gha: bump sigstore/cosign-installer from 3.7.0 to 3.8.0 (#645)

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](sigstore/cosign-installer@dc72c7d...c56c2d3)

---
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/release.yml

@@ -87,7 +87,7 @@ jobs:
             ${{ runner.os }}-go-
 
       - name: Cosign
-        uses: sigstore/cosign-installer@dc72c7d5c4d10cd6bcb8cf6e3fd625a9e5e537da # v1.4.1
+        uses: sigstore/cosign-installer@c56c2d3e59e4281cc41dea2217323ba5694b171e # v1.4.1
 
       - name: Generate SBOM
         uses: anchore/sbom-action/download-syft@f325610c9f50a54015d37c8d16cb3b0e2c8f4de0 # v0.6.0