fix: replace PAT with GITHUB_TOKEN in cleanup-dp workflow (#41699)

Author: wyattwalter

.github/workflows/cleanup-dp.yml

@@ -8,6 +8,9 @@ on:
 jobs:
   execute:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: read
     steps:
       # Checkout the code
       - uses: actions/checkout@v2
@@ -40,7 +43,7 @@ jobs:
           DB_USERNAME: ${{ secrets.DB_USERNAME }}
           DB_PASSWORD: ${{ secrets.DB_PASSWORD }}
           DB_URL: ${{ secrets.DB_URL }}
-          GH_TOKEN: ${{ secrets.APPSMITH_DEPLOY_PREVIEW_PAT }}
+          GH_TOKEN: ${{ github.token }}
           DP_EFS_ID: ${{ secrets.APPSMITH_DP_EFS_ID }}
 
         run: /bin/bash ./scripts/cleanup_dp.sh