Skip HTTP/3 conformance tests on macOS (#159)

Signed-off-by: Anuraag Agrawal <anuraaga@gmail.com>

Author: anuraaga

conformance/test/test_client.py

@@ -22,12 +22,13 @@
     "Client Cancellation/**",
 ]
 
-_flaky_tests = []
+_skipped_tests = []
 if sys.platform == "darwin":
     # TODO: Investigate HTTP/3 conformance test failures on macOS more.
     # Currently, it seems to be an issue with the conformance runner itself and we see this log message.
     # 2026/03/05 01:54:19 failed to sufficiently increase receive buffer size (was: 768 kiB, wanted: 7168 kiB, got: 6144 kiB). See https://github.com/quic-go/quic-go/wiki/UDP-Buffer-Sizes for details.
-    _flaky_tests += ["--known-flaky", "**/HTTPVersion:3/**"]
+    # known-flaky does not work for these errors for some reason so we just skip.
+    _skipped_tests += ["--skip", "**/HTTPVersion:3/**"]
 
 
 def test_client_sync(cov: Coverage | None) -> None:
@@ -45,7 +46,7 @@ def test_client_sync(cov: Coverage | None) -> None:
             "--mode",
             "client",
             *_skipped_tests_sync,
-            *_flaky_tests,
+            *_skipped_tests,
             "--",
             *args,
         ],
@@ -72,7 +73,7 @@ def test_client_async(cov: Coverage | None) -> None:
             _config_path,
             "--mode",
             "client",
-            *_flaky_tests,
+            *_skipped_tests,
             "--",
             *args,
         ],