change ref to pr branch

Author: JenabaBa

.github/workflows/update-dependencies.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: main
+          ref: ${{ github.head_ref }}
 
       - name: build dependency updater
         run: cd dependency_updater && go build