test(clink): use os.pathsep for PATH assertions

Author: syf2211

tests/test_clink_codex_path_resolution.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import asyncio
+import os
 import stat
 from pathlib import Path
 
@@ -68,4 +69,4 @@ async def fake_create_subprocess_exec(*args, **_kwargs):
     assert captured["args"][0] == str(codex_path)
     env = captured["env"]
     assert env is not None
-    assert str(nvm_bin) in env["PATH"].split(":")
+    assert str(nvm_bin) in env["PATH"].split(os.pathsep)