fix(rocm): Use refresh_env_variables() for rocm_aiter_ops in test_moe (#31711)

Signed-off-by: rabi <ramishra@redhat.com>

tests/kernels/moe/test_moe.py

@@ -6,8 +6,6 @@ Run `pytest tests/kernels/test_moe.py`.
 """
 
 import functools
-import importlib
-import sys
 from collections.abc import Callable
 from dataclasses import dataclass
 from typing import Any
@@ -592,14 +590,12 @@ def test_mixtral_moe(
     """Make sure our Mixtral MoE implementation agrees with the one from
     huggingface."""
 
-    # clear the cache before every test
-    # Force reload aiter_ops to pick up the new environment variables.
-    if "rocm_aiter_ops" in sys.modules:
-        importlib.reload(rocm_aiter_ops)
+    # Explicitly set AITER env var based on test parameter to ensure
+    # consistent behavior regardless of external environment
+    monkeypatch.setenv("VLLM_ROCM_USE_AITER", "1" if use_rocm_aiter else "0")
+    rocm_aiter_ops.refresh_env_variables()
 
-    if use_rocm_aiter:
-        monkeypatch.setenv("VLLM_ROCM_USE_AITER", "1")
-        if dtype == torch.float32:
+    if use_rocm_aiter and dtype == torch.float32:
         pytest.skip("AITER ROCm test skip for float32")
 
     monkeypatch.setenv("RANK", "0")