correct checkout (#2945)

Author: MatthewMiddlehurst

.github/workflows/pr_precommit.yml

@@ -65,8 +65,19 @@ jobs:
     runs-on: ubuntu-24.04
 
     steps:
+      - name: Create app token
+        uses: actions/create-github-app-token@v2
+        id: app-token
+        with:
+          app-id: ${{ vars.PR_APP_ID }}
+          private-key: ${{ secrets.PR_APP_KEY }}
+
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
+          ref: ${{ github.head_ref }}
+          token: ${{ steps.app-token.outputs.token }}
 
       - name: Annotate locations with typos
         uses: codespell-project/codespell-problem-matcher@v1