fix class_metadata and regression test

[oopscompiled]

Summary

This PR addresses issue #2371 by reporting inconsistent type args when the same direct base class appears with different type parameters across inheritance paths. It also adds a regression test

Fixes #2371

Test Plan

python3 test.py

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[Copilot]

Pull request overview

Fixes pyrefly’s handling of inconsistent generic type arguments when the same direct base class is reached through multiple inheritance paths with different type parameters (Issue #2371), and updates the existing regression test to assert the expected diagnostic.

Changes:

• Add detection + error reporting for conflicting type arguments associated with a direct base class during MRO linearization.
• Update the regression test to expect the new InvalidInheritance error (and remove the “known bug” marker).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
pyrefly/lib/alt/types/class_metadata.rs	Tracks seen ancestors’ instantiated ClassTypes and emits an InvalidInheritance error when a direct base class is encountered with inconsistent type arguments across inheritance paths.
pyrefly/lib/test/generic_basic.rs	Converts the prior “bug-marked” test into an asserting regression test by adding an # E: expected error on the inconsistent base instantiation.

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[migeed-z]

Thank you for the contribution!
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[meta-codesync]

@migeed-z has imported this pull request. If you are a Meta employee, you can view this in D92869958.

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

core (https://github.com/home-assistant/core)
+ ERROR homeassistant/components/tesla_fleet/entity.py:180:7-36: Class `TeslaFleetWallConnectorEntity` has inconsistent type arguments for base class `CoordinatorEntity`: `CoordinatorEntity[TeslaFleetEnergySiteHistoryCoordinator | TeslaFleetEnergySiteInfoCoordinator | TeslaFleetEnergySiteLiveCoordinator | TeslaFleetVehicleDataCoordinator]` and `CoordinatorEntity[TeslaFleetEnergySiteLiveCoordinator]` [invalid-inheritance]
+ ::error file=homeassistant/components/tesla_fleet/entity.py,line=180,col=7,endLine=180,endColumn=36,title=Pyrefly invalid-inheritance::Class `TeslaFleetWallConnectorEntity` has inconsistent type arguments for base class `CoordinatorEntity`: `CoordinatorEntity[TeslaFleetEnergySiteHistoryCoordinator | TeslaFleetEnergySiteInfoCoordinator | TeslaFleetEnergySiteLiveCoordinator | TeslaFleetVehicleDataCoordinator]` and `CoordinatorEntity[TeslaFleetEnergySiteLiveCoordinator]`

mkdocs (https://github.com/mkdocs/mkdocs)
+ ERROR mkdocs/plugins.py:493:7-23: Class `PluginCollection` has inconsistent type arguments for base class `MutableMapping`: `MutableMapping[Unknown, Unknown]` and `MutableMapping[str, BasePlugin[Unknown]]` [invalid-inheritance]
+ ::error file=mkdocs/plugins.py,line=493,col=7,endLine=493,endColumn=23,title=Pyrefly invalid-inheritance::Class `PluginCollection` has inconsistent type arguments for base class `MutableMapping`: `MutableMapping[Unknown, Unknown]` and `MutableMapping[str, BasePlugin[Unknown]]`

[stroxler]

Review automatically exported from Phabricator review in Meta.

[meta-codesync]

@migeed-z merged this pull request in f4ddc2c.