feat(docker): make containers multi-arch

[AtomicFS]

This makes all of our containers multi-architectural / multi-platform and fixes #341 .

At the moment we only support x86_64 (aka amd64) and arm64 (specifically arm64 v8).

Todo:

• uroot (this was no work)
• linux (this was easy)
• coreboot (took some effort but works)
• edk2 (this is pain)
  • build the toolchains on the fly for non-x86 architectures (first use by user)
    • this is kinda difficult to test at the moment

There is a lot to comprehend, so here are some notes as to why:

• u-root and linux are OK to build the "normal way", however with edk2 and coreboot I get errors when trying to compile to tool-chains - I suspect the problem to be native emulation not supporting all of the instructions required
  • building x86 on x86 machine and arm64 on arm64 works fine, but building arm64 on x86 machine is broken (and vice versa)
• this means that I cannot build edk2 or coreboot multi-arch container on single x86 machine as I can u-root or linux
• I looked into cross-compilation - aka cross-compile the cross-compilation tool-chains ... well that did not go well
  • it should be possible, but it seems like a long process not worth the time investment
• one way would be to build each arch-container separately (x86 part on x86 machine and arm64 part on arm64 machine), publish them separately and then publish hand-crafted manifest connecting them together ... (see The hard way with docker manifest in Multi-arch build and images, the simple way
• but we can avoid all of that with simply compiling the tool-chains separately on their respective machines and then just copy files into single multi-arch container (which can be done without any problems with simple native emulation)
  • UPDATE: coreboot is fine, but edk2 is too much hassle (see feat(docker): compile toolchains separately #368)
• one advantage of separate tool-chain compilation is that this way we can cache the compiled tool-chains for coreboot and speed up the build by one order of magnitude (normally they take around 1 hour to compile)
• as I was running out of disk-space for coreboot docker container I decided to use upx to compress the toolchain reducing the size from around 1.5 GB down to 1.0 GB (as a nice side-effect the whole container is smaller)
• as it stands now, we are not testing if the multi-arch containers work on other than x86 architectures, since it is not really possible right now. We can only verify that the new changes did not break existing functionality.

This is the final PR in the multi-arch saga, which contains breaking changes.

• chore(docker): add omitted arguments into compose file #355
• ci(docker): build monthly instead of weekly #356
• docs: cosmetic changes according to megalinter #359
• style: cosmetic change in edk2 test script #360
• feat: dockerfile support multi arch #361
• ci(docker): dynamically generate the matrix #362
• chore(docker): add omitted arguments into compose file #366
• fix(docker): bump all linux docker containers to noble release #367
• feat(docker): compile toolchains separately #368

[AtomicFS]

The linting issue is a known bug

[MDr164]

What is the purpose of outputting the content of the variable here? Just for debugging? And in the next step you out CACHE_KEY=${CACHE_KEY} aka KEY=VALUE and here just VALUE. Was that done on purpose?