doc tests: Reduce work for test_api_doc_endpoints.

We eliminate 220 zephyr-related checks that are all fairly
expensive.

On my machine this test went from 46s to 23s.

Note that we still get coverage of the zephyr codepath
from other tests.

zerver/tests/test_docs.py

@@ -181,7 +181,15 @@ class DocPageTest(ZulipTestCase):
 
         for endpoint in endpoint_list:
             url = f"/api/{endpoint}"
-            self._test(url, "", doc_html_str=True)
+            self._test_normal_path(
+                url=url,
+                expected_content="",
+                extra_strings=[],
+                landing_missing_strings=[],
+                landing_page=True,
+                doc_html_str=True,
+                search_disabled=False,
+            )
 
     def test_api_doc_404_status_codes(self) -> None:
         result = self.client_get(