ci: add workflow_dispatch trigger

.github/workflows/fly.yml

@@ -3,13 +3,15 @@ name: Deploy to Fly
 on:
   push:
     branches: ["main"]
+  workflow_dispatch:
 
 jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
       - name: Wait for other checks to succeed
         uses: lewagon/[email protected]
+        if: ${{ github.event_name != 'workflow_dispatch' }}
         with:
           ref: ${{ github.ref }}
           running-workflow-name: deploy