Flake8-annotations

Added
* 131 Add the `ANN4xx` error level for opinionated warnings that are disabled by default.
* 131 Add `ANN401` for use of `typing.Any` as an argument annotation.

Changed
* Python 3.7 is now the minimum supported version

Added
* 122 Add support for Flake8 v4.x
Fixed
* 117 Stop including `CHANGELOG.md` when building wheels.

Fixed
* 107, 108 Change incorrect column index yielded for return annotation errors.

Changed
* Remove the explicitly pinned minor version ceiling for flake8.

Added
* 98 Add `--dispatch-decorators` to support suppression of all errors from functions decorated by decorators such as `functools.singledispatch` and `functools.singledispatchmethod`.
* 99 Add `--overload-decorators` to support generic aliasing of the `typing.overload` decorator.

Fixed
* 106 Fix incorrect parsing of multiline docstrings with less than two lines of content, causing incorrect line numbers for yielded errors in Python versions prior to 3.8

Added
* 103 Add `--allow-untyped-nested` to suppress all errors from dynamically typted nested functions. A function is considered dynamically typed if it does not contain any type hints.