Add image generation with aarch64 runtimes

[tytan652]

When using the builder action with aarch64 as arch, the action always install aarch64 runtime.

To avoid this, generating x86_64 images with aarch64 runtime is a solution.

Making images per runtime architecture avoid to make images bigger in size.

Images are tagged with a tag suffixed with the runtime arch, this allow using matrix with containers.
x86_64 runtime images are still also tagged with a non-suffixed tag.

This PR was not tested and two of the checks are failing because images with new tags do not exist.

[GeorgesStavracas]

This probably needs #82 first so you can try and publish these new images to your fork, and then test it there.

[tytan652]

This probably needs #82 first so you can try and publish these new images to your fork, and then test it there.

The reason that I put this PR as draft is to wait for #82, even if I don't want to mess my registry that I never used.

[bilelmoussaoui]

See also #124

[bilelmoussaoui]

We no longer get into this business, flathub takes care of providing the images. Closing this one.