[V0 Deprecation] Remove LLMEngine (#25033)

Signed-off-by: Woosuk Kwon <woosuk@thinkingmachines.ai>
Signed-off-by: Woosuk Kwon <woosuk.kwon@berkeley.edu>

tests/plugins_tests/test_platform_plugins.py

@@ -7,15 +7,6 @@ import torch
 from vllm.plugins import load_general_plugins
 
 
-@pytest.fixture(scope="function", autouse=True)
-def use_v0_only(monkeypatch):
-    """
-    Since this module is V0 only, set VLLM_USE_V1=0 for
-    all tests in the module.
-    """
-    monkeypatch.setenv('VLLM_USE_V1', '0')
-
-
 def test_platform_plugins():
     # simulate workload by running an example
     import runpy