fix: 머지 후 브랜치 삭제 github action 수정

Author: hanseulhee

.github/delete-merged-branch-config.yml

@@ -4,12 +4,11 @@ on:
   pull_request:
     types: [closed]
 
-permissions:
-  pull-requests: write
-
 jobs:
   delete-branch:
     runs-on: ubuntu-latest
     steps:
       - name: delete branch
         uses: SvanBoxel/delete-merged-branch@main
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}