ci: use new token app for automerge workflow

Author: tboerger

.github/workflows/automerge.yml

@@ -11,7 +11,6 @@ name: automerge
 permissions:
   contents: write
   pull-requests: write
-  issues: write
 
 jobs:
   dependabot:
@@ -20,14 +19,14 @@ jobs:
 
     steps:
       - name: Generate token
-        uses: tibdex/github-app-token@3beb63f4bd073e61482598c45c71c1019b59b73a # v2
+        id: token
+        uses: actions/create-github-app-token@7e473efe3cb98aa54f8d4bac15400b15fad77d94 # v2
         with:
-          app_id: ${{ secrets.TOKEN_EXCHANGE_APP }}
-          installation_retrieval_mode: id
-          installation_retrieval_payload: ${{ secrets.TOKEN_EXCHANGE_INSTALL }}
-          private_key: ${{ secrets.TOKEN_EXCHANGE_KEY }}
-          permissions: >-
-            {"contents": "write", "pull_requests": "write", "issues": "write"}
+          app-id: ${{ secrets.TOKEN_EXCHANGE_APP }}
+          private-key: ${{ secrets.TOKEN_EXCHANGE_KEY }}
+          permission-contents: write
+          permission-pull-requests: write
+          permission-issues: write
 
       - name: Fetch metadata
         uses: dependabot/fetch-metadata@08eff52bf64351f401fb50d4972fa95b9f2c2d1b # v2