ci: update deploy wf

.github/workflows/main.yml

@@ -1,14 +1,24 @@
-name: Fly Deploy
-on: [push]
-env:
-  FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
+name: 🚀 Deploy
+on:
+  push:
+    branches:
+      - main
+  pull_request: {}
+
 jobs:
   deploy:
-      name: Deploy app
-      runs-on: ubuntu-latest
-      steps:
-        - uses: actions/checkout@v2
-        - uses: superfly/flyctl-actions@1.1
-          with:
-            args: "deploy"
+    name: 🚀 Deploy
+    runs-on: ubuntu-latest
+    # only build/deploy main branch on pushes
+    if: ${{ github.ref == 'refs/heads/main' && github.event_name == 'push' }}
 
+    steps:
+      - name: ⬇️ Checkout repo
+        uses: actions/checkout@v2
+
+      - name: 🚀 Deploy
+        uses: superfly/flyctl-actions@1.1
+        with:
+          args: "deploy --remote-only"
+        env:
+          FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}