ci(action): update sigstore/cosign-installer action to v4

Author: descope[bot]

.github/actions/pack/action.yml

@@ -172,7 +172,7 @@ runs:
         subject-digest: ${{ steps.push.outputs.digest }}
         push-to-registry: true
     - name: Install Cosign
-      uses: sigstore/cosign-installer@7e8b541eb2e61bf99390e1afd4be13a184e9ebc5 # v3.10.1
+      uses: sigstore/cosign-installer@faadad0cce49287aee09b3a48701e75088a2c6ad # v4.0.0
 
     - name: Sign the image with Cosign (keyless)
       shell: bash