chore: bump sigstore/cosign-installer from 3.5.0 to 3.6.0

Bumps [sigstore/cosign-installer](https://github.com/sigstore/cosign-installer) from 3.5.0 to 3.6.0.
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](sigstore/cosign-installer@v3.5.0...v3.6.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/nightly-docker-build.yaml

@@ -67,7 +67,7 @@ jobs:
           tags: ghcr.io/${{ github.repository }}:nightly
           labels: ${{ steps.meta.outputs.labels }}
 
-      - uses: sigstore/cosign-installer@v3.5.0
+      - uses: sigstore/cosign-installer@v3.6.0
 
       - name: Image Signing
         run: |