chore(deps) Update dependency mypy to ^0.991

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
mypy (source, changelog)	^0.990 -> ^0.991

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Release Notes

python/mypy

### [`v0.991`](https://togithub.com/python/mypy/compare/v0.990...v0.991) [Compare Source](https://togithub.com/python/mypy/compare/v0.990...v0.991)

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[christopherpickering]

:tada: This PR is included in version 1.1.0 :tada:

The release is available on GitHub release

Your semantic-release bot :package::rocket: