mypy doesn't escape typevars from generics in self-type

Bug Report

Passing a callable to another which matches the typevar with another typevar doesn't allow passing them into the return type. (if that makes no sense, the reproducer below is simple)

To Reproduce

from typing import Generic, TypeVar, Callable

T = TypeVar("T")
V = TypeVar("V")

class X(Generic[T]):
    def f(self: X[Callable[[V], None]]) -> Callable[[V], V]:
        def inner_f(v: V) -> V:
            return v

        return inner_f

reveal_type(X[Callable[[T], None]]().f())  # N: Revealed type is "def (Never) -> Never"
# ^ this should keep the generic

Expected Behavior

I don't expect a Never.

Your Environment

Checked on mypy playground.

• Mypy version used: v1.14
• Mypy command-line flags: --strict
• Mypy configuration options from mypy.ini (and other config files): N/A
• Python version used: 3.12

Start by running the provided generic self-type reproducer under mypy v1.14 with --strict and inspect how reveal_type resolves XCallable[[T], None].f(). Trace the type inference path responsible for the result, and consider the issue complete when the returned callable preserves its generic type instead of becoming (Never) -> Never.