invalid-name type alias false-positive for union values

[The-Compiler]

Bug description

With something like:

# pylint: disable=missing-docstring
from typing import Union
x: Union[str, int] = 42

pylint claims a wrong type alias name, with no type aliases involved.

Configuration

No response

Command used

pylint test.py

Pylint output

************* Module test
.../test.py:3:0: C0103: Type alias name "x" doesn't conform to predefined naming style (invalid-name)

Expected behavior

No output

Pylint version

pylint 2.17.0
astroid 2.15.0
Python 3.10.10 (main, Mar  5 2023, 22:26:53) [GCC 12.2.1 20230201]

also reproducible with the current main branches:

pylint 3.0.0a6
astroid 2.16.0dev0
Python 3.10.10 (main, Mar  5 2023, 22:26:53) [GCC 12.2.1 20230201]

OS / Environment

No response

Additional dependencies

No response

[The-Compiler]

Weirdly enough, the PR even adjusts an existing test to fit this (IMHO clearly wrong) naming scheme for a variable (not a type!): https://github.com/PyCQA/pylint/pull/7116/files#diff-53259554143b2179e9e991fecf0879ac4c0eaf61d5f58360ce4491c62f72c6b5

[DanielNoord]

Which test are you referring to in that diff?

[The-Compiler]

tests/functional/r/regression_02/regression_3979.py with:

-foo: Union[str, BasePathLike] = "bar"
+Foo: Union[str, BasePathLike] = "bar"

[DanielNoord]

That fix is because we disallow foo as variable name in our configuration and this now gets flagged because we started checking these kind of assignments.

But, this is indeed a false positive that flew under the radar. I'm checking if I can easily fix this!