Remove download docker client functionality

[LewisGaul]

Removes dependency on typer/tqdm/requests by dropping support for downloading the docker client.

Initially agreed at #512 (comment), this has been deprecated since #577 (v0.71.0 released in April 2024), and agreed we can now remove at #552 (comment). If accepted, this supercedes #513 as a resolution to #512. We will also be able to close #575.

[LewisGaul]

@gabrieldemarmiesse are we ready to merge this do you think?

[gabrieldemarmiesse]

I'm deeply sorry for the late reply there. Thanks for the PR and the description. I believe we should have a section of the docs dedicated to installing the docker cli without the engine since people whose code won't work anymore will look for a solution and might not be aware that they need an apt-get or similar to replace the "download-cli". If you wish, that can be in another PR, but we should write that up before making a release.

[LewisGaul]

Can we just link to https://docs.docker.com/engine/install/ and https://podman.io/docs/installation? Where in the docs were you thinking this should go?

[gabrieldemarmiesse]

We should definitely link those.
I think the instructions should go to https://gabrieldemarmiesse.github.io/python-on-whales/docker_client/

I'm not sure linking is enough, we should additionally tell users that they don't need the engine and containerd and don't need to use systemd or systemctl to create the docker service.

The docker docs are not great if you just want to install the client so we should fill this gap. We just need to tell users what steps are not needed.

We can also add a link to this in our README, just after the pip install.