CI mac: install jq only if not installed

refer the commit d10a9d5c

.github/workflows/ccpp.yml

@@ -215,7 +215,7 @@ jobs:
       id: upload-release
       if: (github.repository == 'CESNET/UltraGrid' && github.ref == 'refs/heads/master') || startsWith(github.ref, 'refs/tags/')
       run: |
-        brew install jq
+        brew list jq >/dev/null || brew install jq
         .github/scripts/replace-asset.sh $TAG UltraGrid-$VERSION.dmg application/x-apple-diskimage macOS%20$(uname -m)%20build
     - name: Upload Build
       if: steps.upload-release.conclusion == 'skipped'