flake8 ignores exclude configuration when used through pre-commit hooks

**Describe the bug**
When sharpy-sc2's pre-commit hooks are installed, flake8 will ignore excludes configured in .flake8 file.

This is by design, and pre-commits exclude should be used instead.

> Checked-in python files will be passed as positional arguments. flake8 will always lint explicitly passed arguments (flake8 --exclude has no effect). **Instead use pre-commit’s exclude**: ... regex to exclude files. pre-commit won’t ever pass untracked files to flake8 so excluding .git / .tox / etc. is unnecessary.

https://flake8.pycqa.org/en/latest/user/using-hooks.html

**Expected behavior**
Flake8 should work in similar way, whether launched with eg. `py -m flake8` or by the pre-commit hooks (installed by `pre-commit install`).

**Additional context**

sharpy-sc2 repo already contains multiple config files with the same excludes.

1. [.flake8](https://github.com/DrInfy/sharpy-sc2/blob/develop/.flake8)
1. [pyproject.toml](https://github.com/DrInfy/sharpy-sc2/blob/develop/pyproject.toml) for Black config
1. [pytest.ini](https://github.com/DrInfy/sharpy-sc2/blob/develop/pytest.ini)

Adding a fourth file with the same excluded directories would be... less than ideal.