[BugFix][CI] Fix scheduler plugin test (#45897)

Signed-off-by: Nick Hill <nickhill123@gmail.com>

tests/plugins_tests/test_scheduler_plugins.py

@@ -10,7 +10,7 @@ from vllm.v1.engine.llm_engine import LLMEngine
 
 
 class DummyV1Scheduler(Scheduler):
-    def schedule(self):
+    def schedule(self, throttle_prefills: bool = False):
         raise Exception("Exception raised by DummyV1Scheduler")