Update workflow to trigger only on merged PR to main

.gitea/workflows/deploy.yml

@@ -1,12 +1,14 @@
 name: Deploy to Scaleway
 
 on:
-  push:
+  pull_request:
+    types: [closed]
     branches:
       - main
 
 jobs:
   build-and-deploy:
+    if: github.event.pull_request.merged == true
     runs-on: ubuntu-latest
     
     steps:
@@ -44,7 +46,3 @@ jobs:
       - name: Deploy to Scaleway Object Storage
         run: |
           s3cmd sync --delete-removed --acl-public public/ s3://${{ secrets.SCW_BUCKET_NAME }}/
-      
-      - name: Invalidate cache (optional)
-        run: |
-          echo "If using Scaleway CDN, add cache invalidation here"