ci: allow workflow_dispatch to trigger draft-release job

Author: kenryu42

.github/workflows/ci.yml

@@ -115,7 +115,7 @@ jobs:
   draft-release:
     runs-on: ubuntu-latest
     needs: [build]
-    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    if: (github.event_name == 'push' || github.event_name == 'workflow_dispatch') && github.ref == 'refs/heads/main'
     permissions:
       contents: write
     steps: