fix: applied josh's suggestions

tips-and-workarounds.md

@@ -48,10 +48,16 @@ on:
   pull_request:
     types:
       - closed
+  workflow_dispatch:
 
 jobs:
   cleanup:
     runs-on: ubuntu-latest
+    permissions:
+      # `actions:write` permission is required to delete caches
+      #   See also: https://docs.github.com/en/rest/actions/cache?apiVersion=2022-11-28#delete-a-github-actions-cache-for-a-repository-using-a-cache-id
+      actions: write
+      contents: read
     steps:
       - name: Cleanup
         run: |
@@ -70,10 +76,6 @@ jobs:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           GH_REPO: ${{ github.repository }}
           BRANCH: refs/pull/${{ github.event.pull_request.number }}/merge
-          done
-          echo "Done"
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 ```
 
 </details>