Run multi-kernel Go tests (vmtests) on arm64

[mtardy]

After some work, LVH now supports arm64 and produces all the needed images, we can use that to run Tetragon's vmtests on arm64.

The only limitation, as of now, is that the available arm64 platforms do not provide nested virtualization (for hardware and software reasons) so we might need to use emulation like we did before for amd64.

### Multi-kernel support for arm64
- [x] LVH was ported to work for arm64 (building kernels & images and running them): [see the list of PRs](https://github.com/cilium/little-vm-helper/pulls?q=is%3Apr+author%3Amtardy+merged%3A2024-03-01..2024-04-18+)
- [x] LVH images CI was ported to build and publish multi-arch kernels & images: [see the list of PRs](https://github.com/cilium/little-vm-helper-images/pulls?q=is%3Apr+author%3Amtardy+merged%3A2024-03-01..2024-04-18+)
- [ ] https://github.com/cilium/tetragon/pull/2333
- [ ] https://github.com/cilium/tetragon/pull/2343