refactor: Pass *Task directly to runSteps

[mrnugget]

This is a tiny follow-up to #540 and removes the TODO that Adam confirmed in his review.

It simplifies things by passing *Task directly to runSteps.

[courier-new]

That's so much nicer, great call! 😄

[LawnGnome]

If there was ever an argument for loose coupling of task and the executor, it went out the window when we copied damn near every field on the task into the options anyway. Good thinking!

[mrnugget]

If there was ever an argument for loose coupling of task and the executor, it went out the window when we copied damn near every field on the task into the options anyway. Good thinking!

Yeah, I also think of the executor now more as "the thing that executes tasks" vs. "the thing that executes steps", now with the Coordinator and the TaskBuilder also doing part of the stuff that the executor previously did.