fix(ci): skip E2E tests when REPO_GEMINI_API_KEY is not set (#972)

* fix(ci): skip E2E tests when REPO_GEMINI_API_KEY is not set

* Update a2ui

* ci: allow forks with Gemini API key to run E2E tests

Author: gspencergoog

.github/workflows/e2e.yaml

@@ -14,7 +14,7 @@ jobs:
   eval-job:
     # Do not run on forked branches,
     # because the test does not have access to secrets in forks.
-    if: github.repository == 'flutter/genui'
+    if: secrets.REPO_GEMINI_API_KEY != ''
     runs-on: ubuntu-latest
     environment: eval
     steps: