## Summary
fixes: https://github.com/astral-sh/ty/issues/2027
This PR fixes a bug where the type mapping for a `ParamSpec` was not
being applied in an overloaded function.
This PR also fixes https://github.com/astral-sh/ty/issues/2081 and
reveals new diagnostics which doesn't look related to the bug:
```py
from prefect import flow, task
@task
def task_get() -> int:
"""Task get integer."""
return 42
@task
def task_add(x: int, y: int) -> int:
"""Task add two integers."""
print(f"Adding {x} and {y}")
return x + y
@flow
def my_flow():
"""My flow."""
x = 23
future_y = task_get.submit()
# error: [no-matching-overload]
task_add(future_y, future_y)
# error: [no-matching-overload]
task_add(x, future_y)
```
The reason is that the type of `future_y` is `PrefectFuture[int]` while
the type of `task_add` is `Task[(x: int, y: int), int]` which means that
the assignment between `int` and `PrefectFuture[int]` fails which
results in no overload matching. Pyright also raises the invalid
argument type error on all three usages of `future_y` in those two
calls.
## Test Plan
Add regression mdtest from the linked issue.
2190fcebe0