chore: vendor sglang v0.5.10 snapshot

third_party/sglang/sgl-model-gateway/e2e_test/fixtures/ports.py

@@ -0,0 +1,14 @@
+"""Legacy port utilities.
+
+DEPRECATED: This module will be removed during e2e_response_api migration.
+Use infra.get_open_port() instead.
+"""
+
+import socket
+
+
+def find_free_port() -> int:
+    """Return an available TCP port on localhost."""
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+        s.bind(("127.0.0.1", 0))
+        return s.getsockname()[1]