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Hey all. I've been struggling recently with a type error from Pyright with my flows. I've just upgraded to Prefect 3.1.7. I'll thread the error I'm getting so they don't clutter.

When I decorate a flow  simply with `@flow`, everything is fine. When I try to add arguments, such as `@flow(task_runner=ThreadPoolTaskRunner(max_workers=3))` , I get the error in the thread.

Thanks in advance for any help!

```Argument of type "ThreadPoolTaskRunner" cannot be assigned to parameter "task_runner" of type "TaskRunner[PrefectFuture[R@flow]] | None" in function "flow"
  Type "ThreadPoolTaskRunner" is incompatible with type "TaskRunner[PrefectFuture[R@flow]] | None"
    "ThreadPoolTaskRunner" is incompatible with "TaskRunner[PrefectFuture[R@flow]]"
      Type parameter "F@TaskRunner" is invariant, but "PrefectConcurrentFuture[Unknown]" is not the same as "PrefectFuture[R@flow]"
    "ThreadPoolTaskRunner" is incompatible with "None"PylancereportArgumentType```

Might be related to this issue
<https://github.com/PrefectHQ/prefect/issues/16396>

I'm running into this problem as well. Looking at the source code, I see <https://github.com/PrefectHQ/prefect/blob/e448bd3462d7c2580427624f426d81cf6e9a7ff1/src/prefect/flows.py#L1427|task_runner is of type None>, which is very odd.