ci: set checkout ref

.github/workflows/auto-fix.yml

@@ -1,10 +1,8 @@
 name: auto-fix
 
 on:
-  push:
-    branches:
-      - master
   pull_request:
+  push:
     branches:
       - master
 
@@ -16,6 +14,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
 
       - uses: pnpm/action-setup@v4