Bump sigstore/cosign-installer from 2.8.1 to 3.1.2 (#3170)

Bumps [sigstore/cosign-installer](https://github.com/sigstore/cosign-installer) from 2.8.1 to 3.1.2.
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](sigstore/cosign-installer@v2.8.1...v3.1.2)

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

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

.github/workflows/docker-image.yaml

@@ -29,7 +29,7 @@ jobs:
           submodules: "recursive"
 
       - name: Install cosign
-        uses: sigstore/cosign-installer@v2.8.1
+        uses: sigstore/cosign-installer@v3.1.2
 
       - name: Log into registry ${{ env.REGISTRY }}
         uses: docker/login-action@v2.1.0