ci: use GitHub app token for upstream workflow (#276)

Author: DanielleHuisman

.github/workflows/upstream.yml

@@ -15,6 +15,13 @@ jobs:
         runs-on: ubuntu-latest
 
         steps:
+            - name: Generate GitHub App token
+              id: app-token
+              uses: actions/create-github-app-token@v2
+              with:
+                  app-id: ${{ secrets.APP_ID }}
+                  private-key: ${{ secrets.APP_PRIVATE_KEY }}
+
             - name: Checkout
               uses: actions/checkout@v6
 
@@ -24,7 +31,8 @@ jobs:
             - name: Check for upstream releases
               run: cargo run -p scripts --bin upstream
               env:
-                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-                  GIT_USER_NAME: github-actions[bot]
-                  GIT_USER_EMAIL: github-actions[bot]@users.noreply.github.com
+                  GITHUB_ACTOR: rust-for-web[bot]
+                  GITHUB_TOKEN: ${{ steps.app-token.outputs.token }}
+                  GIT_USER_NAME: rust-for-web[bot]
+                  GIT_USER_EMAIL: 191031261+rust-for-web[bot]@users.noreply.github.com
                   RUST_LOG: upstream=debug