test_navigation: wait for backend to be available

avoid element not interactable error in github actions

integration/test_navigation.py

@@ -7,7 +7,7 @@
 
 from reflex.testing import AppHarness
 
-from .utils import poll_for_navigation
+from .utils import SessionStorage, poll_for_navigation
 
 
 def NavigationApp():
@@ -66,6 +66,10 @@ async def test_navigation_app(navigation_app: AppHarness):
     assert navigation_app.app_instance is not None, "app is not running"
     driver = navigation_app.frontend()
 
+    ss = SessionStorage(driver)
+    token = AppHarness._poll_for(lambda: ss.get("token") is not None)
+    assert token is not None
+
     internal_link = driver.find_element(By.ID, "internal")
 
     with poll_for_navigation(driver):