fixup! [CI] Draft a homebrew-based macCI.

Author: hageboeck

.github/workflows/root-ci.yml

@@ -122,7 +122,7 @@ jobs:
     runs-on: # Using '[self-hosted, ..., ...]' does not work for some reason :)
       - self-hosted
       - macOS
-      - ${{ matrix.package_manager == 'brew' && 'experimental-brew-ci' }}
+      - ${{ (matrix.package_manager == 'brew' && 'experimental-brew-ci') || '' }}
       - ${{ matrix.arch }}
       - ${{ matrix.platform }}