ci: update sigstore/cosign-installer action to v4

Author: renovate-bot

.github/workflows/dankfedora.yaml

@@ -109,7 +109,7 @@ jobs:
           password: ${{ env.REGISTRY_PASSWORD }}
 
       - name: install cosign
-        uses: sigstore/cosign-installer@7e8b541eb2e61bf99390e1afd4be13a184e9ebc5  # v3.10.1
+        uses: sigstore/cosign-installer@faadad0cce49287aee09b3a48701e75088a2c6ad  # v4.0.0
         if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
 
       - name: sign image

.github/workflows/dankydeck.yaml

@@ -108,7 +108,7 @@ jobs:
           password: ${{ env.REGISTRY_PASSWORD }}
 
       - name: install cosign
-        uses: sigstore/cosign-installer@7e8b541eb2e61bf99390e1afd4be13a184e9ebc5  # v3.10.1
+        uses: sigstore/cosign-installer@faadad0cce49287aee09b3a48701e75088a2c6ad  # v4.0.0
         if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
 
       - name: sign image