CI/CD: Add aliased TARGETARCH builds

[Yurzs]

Issue:

• when using docker to build images depending on s6-overlay Dockers $TARGETARCH env variable for aarch64 is set to arm64, so each multi-arch dependent project have to implement if statement replacing arm64 -> aarch64 in their Dockerfile.

Solution:

• create an alias for aarch64 -> arm64 archive in CI

[skarnet]

The main problem with supporting the TARGETARCH naming pattern is that it duplicates the artifacts. Please read this thread.

I understand this is inconvenient, but I'm not convinced providing twice the amount of files under different names is the answer.

[Yurzs]

I understand this is inconvenient, but I'm not convinced providing twice the amount of files under different names is the answer.

But still the workaround can be implemented so fellow devs don't suffer.
If GitHub implements support for symlinks in the releases then it can be used instead.
500KB file on each release won't do much.

[skarnet]

I'm not adding an exception for aarch64. If you want the problem to be solved, please suggest a solution that works for all architectures. This is not an easy task; we've thought about it, and haven't found anything satisfactory.

It's not only a question of storage, it's also a question of clarity for users. If two tarballs with different names are effectively the same, this can cause confusion.

Having GitHub support for explicit symlinks (displayed as such in the downloads page) would solve both problems at once. Unfortunately, it's not under our control.