fix overloads for wait_for and return_state in Task.__call__

[zzstoatzz]

adds an overload to make the type checker handle wait_for when calling tasks directly, pyright complains on main

also makes various Dict -> dict changes and adds a private alias to make the overloads as shown by IDE easier to grok

main

this branch

example

from prefect import flow, task


@task
def double(x: int) -> int:
    return x * 2


@task
def cast_to_float(x: int) -> float:
    return float(x)


@flow
def flow_with_task() -> float:
    result = double(1)
    other_result = cast_to_float(2, wait_for=[result])
    state = cast_to_float(3, wait_for=[other_result], return_state=True)
    last_value = cast_to_float(4, wait_for=[state.result()], return_state=False)
    return last_value

[codspeed-hq]

CodSpeed Performance Report

Merging #16547 will not alter performance

_{Comparing dunder-call-wait-for-typing (bd3c871) with main (0049987)}

Summary

✅ 3 untouched benchmarks

[desertaxle]

One question about using forward refs in the task engine for stuff from prefect.tasks, but otherwise this is great!