Container pipeline overhaul

[nohoster]

Hello, I decided to optimize the way the container is being build. Currently is really slow since it has to do a fresh compilation every time and also it's using emulation for the arm builds.

Instead I decided to split the process. First compile the redlib binary using cross compilation. This takes only 3 to 4 minutes. And then just copy this binary into a container.

This also allows the building process to reuse dependency cache.

The whole process takes less than 4 minutes in comparison to the 15 to 30 minutes of the current pipeline which is quite an improvement. It also produces a single redlib:latest multiarch container, so there is no need for different tags.

The only detail is that I'm using releases to save the binaries and I'm using the DATE-TIME as the release name since there is no app version updates. You can check the result in my repo.
If you don't like that I can change it into a single pipeline and copy the binary inside the pipeline.

[chowder]

Took me a while to find out today why my changes weren't being reflected in my development containers... :'(

[master-hax]

Currently is really slow since it has to do a fresh compilation every time and also it's using emulation for the arm builds.

FYI there are fixes for this, we did not have to throw away the working Dockerfiles and replace them with one that's a glorified link to github.

one example is libreddit/libreddit#751 where i fixed the fresh compilation issue for the arm builds. is it possible to revert this change and apply the same optimization? it would make building a docker image during development much easier and would not mislead users who are building from a git URL.

[sigaloid]

If you want to do another overhaul to the actions, I wouldn't be opposed to merging - there's been some struggles since this PR in some places. Open an issue describing your motivations and a PR, and I'll take a look. I'm not skilled in GHA in general so I defer to others generally.