Only doing this workflow on the main branch

Author: dmuth

.github/workflows/main.yml

@@ -4,6 +4,7 @@ env:
   FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
 jobs:
   deploy:
+      if: github.ref == 'refs/heads/main'
       name: Deploy app
       runs-on: ubuntu-latest
       steps: