Pre-build M68k for faster Docker build times

[whyitfor]

With #502, CI/CD pipeline time doubles from 20-30 to ~50 minutes.

At least 20 minutes of this time is building the M68K toolchain.
This issue would result in the toolchain being pre-built and downloaded as part of the Docker image build.
For example, a solution could be:

• Creating a new repository with a Dockerfile that builds the toolchain
• Saving a tarball of that build as a release
• Downloading that tarball in when ofrak Docker build happens

Potential issues: ensuring that the M68K toolchain can work with base images that are not python:3.9-bookworm.

Another option could be saving this artifact in the Docker CI/CD pipeline. One downside of this approach is that we do not provide this speedup for other OFRAK users building the Docker image.

Which files would be affected?
ofrak_patch_maker/Dockerstub, potentially others depending on how this is implemented.

Does the proposed maintenance include non-doc string functional changes to the Python code?
No.

[ANogin]

What about publishing a family of M68K toolchain docker images in a public docker image repository, than using that repository as a source of that toolchain both in CI/CD and in regular OFRAK docker builds?

[ANogin]

Alternatively, building it as a .deb and having that published to public repo that could be added to apt as part of the OFRAK dependency install?