Bump actions/create-github-app-token from 2 to 3 (#164)

Author: dependabot[bot]

.github/workflows/flake_update.yaml

@@ -32,7 +32,7 @@ jobs:
 
       - name: Create token
         id: generate-token
-        uses: actions/create-github-app-token@v2
+        uses: actions/create-github-app-token@v3
         with:
           # https://github.com/actions/create-github-app-token/issues/136
           app-id: ${{ secrets.APP_ID }}