Bump sigstore/cosign-installer from 3.8.2 to 3.9.1

Bumps [sigstore/cosign-installer](https://github.com/sigstore/cosign-installer) from 3.8.2 to 3.9.1.
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](sigstore/cosign-installer@v3.8.2...v3.9.1)

---
updated-dependencies:
- dependency-name: sigstore/cosign-installer
  dependency-version: 3.9.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/release-process.yml

@@ -42,7 +42,7 @@ jobs:
           go-version-file: go.mod
 
       - name: Set up Cosign
-        uses: sigstore/cosign-installer@v3.8.2
+        uses: sigstore/cosign-installer@v3.9.1
 
       - name: Run release script
         run: |