Regression in Astroid version 2.15.7 in handling subscriptable type parameters

[behnazh-w]

Astroid version 2.15.7 fails to correctly handle a subscriptable type parameter most likely due to the change in this PR.

Steps to reproduce

from collections.abc import Mapping
from typing import Generic, TypeVar, TypedDict
from dataclasses import dataclass

class Identity(TypedDict):
    """It's the identity."""

    name: str

T = TypeVar("T", bound=Mapping)

@dataclass
class Animal(Generic[T]):
    """It's an animal."""

    identity: T

class Dog(Animal[Identity]):
    """It's a Dog."""

dog = Dog(identity=Identity(name="Dog"))
print(dog.identity["name"])

Current behavior

Pylint (running Astroid 2.15.7) gives the following error for the example above:

E1136: Value 'dog.identity' is unsubscriptable (unsubscriptable-object)

Expected behavior

Astroid should correctly handle a subscriptable type parameter.

python -c "from astroid import __pkginfo__; print(__pkginfo__.version)" output

2.15.7

[jacobtylerwalls]

Thanks for the report.

[jacobtylerwalls]

@mbyrnepr2 Would you be willing to take a look?