ci(release): install cosign for release smoke

Signed-off-by: JSONbored <49853598+JSONbored@users.noreply.github.com>

Author: JSONbored

.github/workflows/release.yml

@@ -209,6 +209,9 @@ jobs:
         with:
           persist-credentials: false
 
+      - name: Install Cosign
+        uses: sigstore/cosign-installer@cad07c2e89fa2edd6e2d7bab4c1aa38e53f76003 # v4.1.1
+
       - name: Smoke published GitHub release artifacts
         env:
           GH_TOKEN: ${{ github.token }}

scripts/test-release-scripts.sh

@@ -33,6 +33,10 @@ grep -q "x86_64-apple-darwin" "${repo_root}/.github/workflows/release.yml"
 grep -q 'NIGHTWARD_VERSION="${version}"' "${repo_root}/.github/workflows/release.yml"
 grep -q "dist/nightward_\\*.tar.gz" "${repo_root}/.github/workflows/release.yml"
 grep -q "dist/nightward_\\*.zip" "${repo_root}/.github/workflows/release.yml"
+if [[ "$(grep -c "sigstore/cosign-installer" "${repo_root}/.github/workflows/release.yml")" -lt 2 ]]; then
+  echo "expected release publish and smoke jobs to install cosign" >&2
+  exit 1
+fi
 if grep -q "path: dist/nightward_\\*" "${repo_root}/.github/workflows/release.yml"; then
   echo "expected release upload to exclude staging directories" >&2
   exit 1