fix: try to run dange in PR correctly (#34375)

Summary:
After #34370, Danger started failing because the `DANGER_GITHUB_API_TOKEN` was not properly set.
This PR fixes it.

## Changelog

[General] [Changed] - Set back the `DANGER_GITHUB_API_TOKEN`.

Pull Request resolved: #34375

Test Plan: Danger GitHub action is executed correctly.

Reviewed By: cortinico

Differential Revision: D38571718

Pulled By: cipolleschi

fbshipit-source-id: 51168098b4f910f6fefd2872f917e12daad1ec4c

.github/workflows/danger_pr.yml

@@ -26,3 +26,5 @@ jobs:
       - name: Danger
         run: yarn danger ci --use-github-checks --failOnErrors
         working-directory: bots
+        env:
+          DANGER_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}