fix pylint E1120 error. (#21230)

* fix pylint E1120 error.

* fix type annotation for py39

* fix mypy error.

* fix mypy error.

* fix mypy error.

* fix wrapper return type.

* refactored `_restricted_classmethod_impl`

* revert refactor

* ignore mypy error.

* resume original type.

* revert mypy.

* attempt fixing macos doctest

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Co-authored-by: Jirka Borovec <6035284+Borda@users.noreply.github.com>
Co-authored-by: Nicki Skafte Detlefsen <skaftenicki@gmail.com>
Co-authored-by: Justus Schock <12886177+justusschock@users.noreply.github.com>