[Misc] Remove the unused LoRA test code (#20494)

Signed-off-by: Jee Jee Li <pandaleefree@gmail.com>

tests/lora/conftest.py

@@ -249,23 +249,6 @@ def llama_2_7b_model_extra_embeddings(llama_2_7b_engine_extra_embeddings):
            model_runner.model)
 
 
-@pytest.fixture(params=[True, False])
-def run_with_both_engines_lora(request, monkeypatch):
-    # Automatically runs tests twice, once with V1 and once without
-    use_v1 = request.param
-    # Tests decorated with `@skip_v1` are only run without v1
-    skip_v1 = request.node.get_closest_marker("skip_v1")
-
-    if use_v1:
-        if skip_v1:
-            pytest.skip("Skipping test on vllm V1")
-        monkeypatch.setenv('VLLM_USE_V1', '1')
-    else:
-        monkeypatch.setenv('VLLM_USE_V1', '0')
-
-    yield
-
-
 @pytest.fixture
 def reset_default_device():
     """