Add permissions: for firebaseai.yml

Author: andrewheard

.github/workflows/firebaseai.yml

@@ -15,6 +15,10 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
+permissions:
+  contents: read  # Needed for actions/checkout
+  actions: write # Needed for actions/cache (save and restore)
+
 jobs:
   spm-package-resolved:
     runs-on: macos-14