ci(tools): update actions/create-github-app-token action to v3

Author: renovate[bot]

.github/workflows/automerge.yml

@@ -20,7 +20,7 @@ jobs:
     steps:
       - name: Generate token
         id: token
-        uses: actions/create-github-app-token@v2
+        uses: actions/create-github-app-token@v3
         with:
           app-id: ${{ secrets.TOKEN_EXCHANGE_APP }}
           private-key: ${{ secrets.TOKEN_EXCHANGE_KEY }}