Bump sigstore/cosign-installer from 3.9.2 to 4.0.0

Bumps [sigstore/cosign-installer](https://github.com/sigstore/cosign-installer) from 3.9.2 to 4.0.0.
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](sigstore/cosign-installer@v3.9.2...v4.0.0)

---
updated-dependencies:
- dependency-name: sigstore/cosign-installer
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/docker-publish.yml

@@ -41,7 +41,7 @@ jobs:
       # https://github.com/sigstore/cosign-installer
       - name: Install cosign
         if: github.event_name != 'pull_request'
-        uses: sigstore/cosign-installer@v3.9.2
+        uses: sigstore/cosign-installer@v4.0.0
 
       # Workaround: https://github.com/docker/build-push-action/issues/461
       - name: Setup Docker buildx