Build aarch64/armhf on ubuntu-24.04-arm

[bastimeyer]

That should fix the recent build errors on aarch64. The runners have been running smoothly on the branch of my fork.
Split into two commits, for the docker-based builds and for the chroot-based builds.

The second commit also removes what looks like a superfluous cp command.

[TheAssassin]

Ah, we're still using qemu here. I thought I had migrated this repository as well.

[bastimeyer]

Would it make sense using the -arm runner for armhf as well? It'd still require qemu, but it might be faster than x86_64.

[TheAssassin]

Yes, it would. See https://github.com/AppImage/appimagetool/blob/main/.github/workflows/build.yml where I changed this already.

[github-actions]

Build for testing:
artifacts x86_64
artifacts i686
artifacts aarch64
artifacts armhf
Use at your own risk.

[probonopd]

@bastimeyer thank you for your efforts to help this project. Really appreciate it!

[github-actions]

Build for testing:
artifacts x86_64
artifacts i686
artifacts aarch64
Use at your own risk.

[github-actions]

Build for testing:
artifacts x86_64
artifacts i686
artifacts aarch64
artifacts armhf
Use at your own risk.

[github-actions]

Build for testing:
artifacts x86_64
artifacts i686
artifacts armhf
artifacts aarch64
Use at your own risk.

[TheAssassin]

Thanks, this really speeds up the builds!