fix inspect.isclass does not make a TypeForm valid for isinstance #4822

[asukaminato0721]

Summary

Fixes #4822

TypeForm values narrowed by inspect.isclass now work with isinstance.

Test Plan

add test

[meta-codesync]

This pull request has been imported. If you are a Meta employee, you can view this in D119017345. (Because this pull request was imported automatically, there will not be any future comments.)

[github-actions]

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

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SUMMARY
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Total: +0 new errors, -1 fixed errors
By preset: +0/-1 (default), +0/-1 (strict)

Projects with changes (1):
  streamlit: +0 -1
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FULL DIFF DETAILS
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streamlit (https://github.com/streamlit/streamlit)
- ERROR lib/streamlit/elements/lib/options_selector_utils.py:168:36-49: Expected class object, got `EnumMeta & type[E2]` [invalid-argument]

[github-actions]

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