pre-commit flake8 saying passed when flake8 fails

[rosesyrett]

I recently checked out #143 to review it, and noticed a flake8 error in my IDE. Upon running flake8, I noticed two E721 errors. In the pre-commit-config.yaml, this error is not being ignored, yet it does not show up when running pre-commit:

(venv) root ➜ .../rose/Documents/projects/dodal (129_edge_detection) $ pre-commit run --all
[INFO] Initializing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Initializing environment for https://github.com/psf/black.
[INFO] Initializing environment for https://github.com/pycqa/isort.
[INFO] Initializing environment for https://github.com/pycqa/flake8.
[INFO] Initializing environment for https://github.com/pycqa/flake8:flake8-comprehensions==3.8.0,Flake8-pyproject.
[INFO] Initializing environment for https://github.com/pre-commit/mirrors-mypy.
[INFO] Initializing environment for https://github.com/pre-commit/mirrors-mypy:types-requests,pydantic.
[INFO] Installing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/psf/black.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/pycqa/isort.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/pycqa/flake8.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/pre-commit/mirrors-mypy.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
check for added large files..............................................Passed
check yaml...............................................................Passed
check for merge conflicts................................................Passed
black....................................................................Passed
isort (python)...........................................................Passed
flake8...................................................................Passed
mypy.....................................................................Passed
(venv) root ➜ .../rose/Documents/projects/dodal (129_edge_detection) $ flake8 src/
src/dodal/beamlines/beamline_utils.py:42:12: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
src/dodal/devices/status.py:24:8: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`

[dperl-dls]

Closing because we're not using flake8 anymore