Misleading error message with `dict.get` like method. (polymorphic function with conflicting context)

Consider this example that emulates dict.get: (https://mypy-play.net/?mypy=latest&python=3.12)

from typing import Any, reveal_type

class Map[K, V]:
    def set(self, key: K, value: V) -> None: ...
    def get[T](self, key: Any, default: T, /) -> V | T: ...

d_any: Map[str, Any] = Map()

reveal_type(d_any.get("key", None))  # Any | None  ✅️

result: str = reveal_type(d_any.get("key", None))  # Any | str ❌️
# error: Argument 2 to "get" of "Map" has incompatible type "None"; expected "str" 

mypys error message is misleading. None is a perfectly reasonable argument for the default value of d_any.get. The problem is that the return type Any | None is not assignable to str. It would make more sense if either:

1. mypy reports that Any | None cannot be assigned to str.
   (e.g. by a two step approach: first try to solve with context and if that fails, use the return type that is inferred from the arguments alone)[^1]
2. mypy reports that it cannot find a solution for the type variable T.
   (e.g. single step that considers both constraints from arguments and context)

[^1]: In certain special cases like tuple/list/set/dict-comprehensions, the current behavior that inverts the priority seems fine

Beginne damit, das Beispiel im verlinkten mypy playground zu reproduzieren, und vergleiche die Diagnose mit den beiden vorgeschlagenen Ergebnissen. Verfolge mypy's generische Typinferenz und sein Verhalten bei der kontextuellen Typisierung für den polymorphen get-Aufruf. Als abgeschlossen gilt die Aufgabe, wenn die Diagnose nicht mehr fälschlicherweise None die Schuld gibt und ein Regressionstest dieses Beispiel abdeckt.