chore: fix llm_root when LLM_ROOT is not set (#4741)

Signed-off-by: Aurelien Chartier <[email protected]>

Author: achartier

tests/unittest/utils/cpp_paths.py

@@ -14,7 +14,7 @@
 def llm_root() -> _pl.Path:
     environ_root = _os.environ.get("LLM_ROOT", None)
     return _pl.Path(environ_root) if environ_root is not None else _pl.Path(
-        __file__).resolve().parent.parent.parent
+        __file__).resolve().parent.parent.parent.parent
 
 
 @pytest.fixture(scope="module")