Fix mypy-specific type check error

Author: dandavison

tests/worker/test_workflow.py

@@ -5558,9 +5558,10 @@ def init(self, params: UseLockOrSemaphoreWorkflowParameters):
     @workflow.run
     async def run(
         self,
-        params: UseLockOrSemaphoreWorkflowParameters,
+        params: Optional[UseLockOrSemaphoreWorkflowParameters],
     ) -> LockOrSemaphoreWorkflowConcurrencySummary:
         # TODO: Use workflow init method when it exists.
+        assert params
         self.init(params)
         await asyncio.gather(
             *(self.coroutine(f"{i}") for i in range(self.params.n_coroutines))
@@ -5615,6 +5616,7 @@ def __init__(self) -> None:
     @workflow.run
     async def run(
         self,
+        _: Optional[UseLockOrSemaphoreWorkflowParameters] = None,
     ) -> LockOrSemaphoreWorkflowConcurrencySummary:
         await workflow.wait_condition(lambda: self.workflow_may_exit)
         return LockOrSemaphoreWorkflowConcurrencySummary(