ci: add permissions to GitHub workflows

Author: robertodauria

.github/workflows/firebase-hosting-merge.yml

@@ -6,6 +6,9 @@ name: Deploy to Firebase Hosting on merge
   push:
     branches:
       - main
+permissions:
+  contents: read
+  checks: write
 jobs:
   build_and_deploy:
     runs-on: ubuntu-latest

.github/workflows/firebase-hosting-pull-request.yml

@@ -3,6 +3,9 @@
 
 name: Deploy to Firebase Hosting on PR
 'on': pull_request
+permissions:
+  contents: read
+  checks: write
 jobs:
   build_and_preview:
     if: '${{ github.event.pull_request.head.repo.full_name == github.repository }}'