codespell was dropped via a63011b3.
Accordingly, this commit does some cleanup.

The previous commit changed the strategy to 'clone', instead of 'fetch'
as before. While this fixes permission errors, it is also slower, as an
existing checkout of the repository will be ignored. To overcome this,
this commit limits the depth to 5.

While the former is slower, the later might lead to errors such as
"fatal: detected dubious ownership in repository at" which is fixed
GitLab upstream via
https://gitlab.com/gitlab-org/gitlab-runner/-/merge_requests/3538, but
not yet released.

Closes #191

Closes #187

Otherwise, this job might fail, depending on the runner which executes
the job, due to different configurations, especially wrt the default
image.

Ref !105

- Remove some useless linters
- Make use of ruff

This reverts commit 29057d6c.

Isn't borderline useless compared to mypy and pylint

Nobody should be using Poppler < 0.46

A zip file with a file pointing to /etc/passwd would, upon being cleaned by
mat2, produce a file with the filesystem's /etc/passwd file.