Revert "Update GITHUB_TOKEN environment variable for Danger (#10365)"

Danger doesn't appear to work with PRs from forks: danger/danger-js#918

Will need to research this some more.

This reverts commit 53d0cc6.

.github/workflows/danger.yml

@@ -32,4 +32,4 @@ jobs:
       - name: Run Danger
         run: pnpm run --dir script/danger danger ci
         env:
-          GITHUB_TOKEN: ${{ secrets.DANGER_GITHUB_API_TOKEN }}
+          GITHUB_TOKEN: ${{ github.token }}