dependabot(deps): bump sigstore/cosign-installer from 3.10.0 to 4.0.0

Bumps [sigstore/cosign-installer](https://github.com/sigstore/cosign-installer) from 3.10.0 to 4.0.0.
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](sigstore/cosign-installer@v3.10.0...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/release.yaml

@@ -24,7 +24,7 @@ jobs:
         with:
           go-version: '1.25'
           cache: true
-      - uses: sigstore/cosign-installer@v3.10.0  # installs cosign
+      - uses: sigstore/cosign-installer@v4.0.0  # installs cosign
 #    - uses: anchore/sbom-action/[email protected]  # installs syft
       - uses: docker/login-action@v3  # login to ghcr
         with: