Needed for building some of the Python packages.

The Debian package currently is uninstallable due to a missing
dependency (python3-typed-ast).

I think that the order of the commands is random and files that were
created were removed. Also, it's not needed.

Add the mdformat packages to the pre-commit hook needed for that. Format
the existing files.

Same statx issue.

- Update base image to Debian Bullseye.
- Use full names for images.
- Use go install instead of go get (it's being deprecated).

I think it should be a part of this project as they are develeoped
hand-in-hand.

Used for building some Golang binaries.

This reverts commit f8148df6.

Dealt with in the CI templates repo.

Show the example presentation. Also, excercise the GitLab CI template.

Because there are scheduled CI runs.

For rsvg2pdf (or rsvg-convert).

After migrating to GitLab.

for pdf2ps.

Add common Docker checks, address some issues.

Also, set `--fail-if-warnings` to fail on warnings.

The missing `/etc/protocols` broke using images from the web. Install
`netbase`.

pdftk is now pdftk-java which drags in the JRE and makes the image even
bigger (and startup times longer). Use qpdf instead.

Useful for manipulating PDF files.