test(local): skip httpbin timeout probe when the service returns 5xx

local_testing_part1 was failing on test_post_delay_exceeds_per_request_timeout_raises
because httpbin.org/delay/10 intermittently answers 503 instead of delaying, so
HTTPHandler.post raised MaskedHTTPStatusError rather than the expected Timeout. The
test already means to skip when httpbin is unavailable, but its guard only probed
GET /get and ignored a server error on the delay endpoint. Treat a 5xx from httpbin as
'service unavailable' and skip, which is outside this repo's control, while still
asserting Timeout when httpbin genuinely delays.

tests/local_testing/test_azure_anthropic_sync_post.py

@@ -18,7 +18,10 @@ import pytest
 sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "../..")))
 
 from litellm.exceptions import Timeout as LitellmTimeout
-from litellm.llms.custom_httpx.http_handler import _get_httpx_client
+from litellm.llms.custom_httpx.http_handler import (
+    MaskedHTTPStatusError,
+    _get_httpx_client,
+)
 
 _HTTPBIN_DELAY_S = 10
 _PER_REQUEST_TIMEOUT_S = 5.0
@@ -40,5 +43,7 @@ def test_post_delay_exceeds_per_request_timeout_raises():
                 data=json.dumps({"model": "claude", "messages": []}),
                 timeout=_PER_REQUEST_TIMEOUT_S,
             )
+    except MaskedHTTPStatusError as e:
+        pytest.skip(f"httpbin.org unavailable: {e}")
     finally:
         handler.close()