chore(deps-dev): Bump mypy from 0.950 to 0.961

Bumps mypy from 0.950 to 0.961.

Commits

• 89bdcfb Update version to 0.961
• 154ac75 Run dataclass plugin before checking type var bounds (#12908)
• f649e2d Fix crash with nested attrs class (#12872)
• 64e9c0d Update version to 0.961+dev
• 0a4a190 Update version to 0.960
• 128661c Friendlier errors for PEP 612 (#12832)
• a54c84d Bring back type annotation support of dunder methods in stub generator (#12828)
• 290f013 FindModuleCache: optionally leverage BuildSourceSet (#12616)
• aa7c21a Typeshed cherry-pick: Ignore mypy errors in Python 2 builtins and typing (#78...
• 644d5f6 checkexpr: cache type of container literals when possible (#12707)
• Additional commits viewable in compare view