CI: Fix HTTP certificate error when requesting example.org from GHA

ConnectionError: Server not available, exception:
HTTPSConnectionPool(host='example.org', port=443):
Max retries exceeded with url: Caused by SSLCertVerificationError
[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed:
unable to get local issuer certificate (_ssl.c:1081)

Author: amotl

docs/by-example/http.rst

@@ -216,7 +216,7 @@ please use the ``urllib3.Timeout`` object like:
 
 When connecting to non-CrateDB servers, the HttpClient will raise a ConnectionError like this:
 
-    >>> http_client = HttpClient(["https://example.org/"])
+    >>> http_client = HttpClient(["https://httpbin.org/html"])
     >>> http_client.server_infos(http_client._get_server())
     Traceback (most recent call last):
     ...