feat: add support for arm64

[michaeldmitry]

Fixes #27

Currently our CI doesn’t run itests using arm runners → fix
But, even when it does, it won’t work for our case. ATM, our self-hosted arm runners + gh arm runners don’t support nested virtualisation. Meaning that, juju won’t be able to deploy a machine of type virtual-machine, which is what we need for the profiler to work.

Sample error logs when trying to run the itests on arm runners

+ .machines['0'].machine_status.current = 'provisioning error'
+ .machines['0'].machine_status.message = 'Failed creating instance record: Instance type "virtual-machine" is not supported on this server: KVM support is missing (no /dev/kvm)'

UPDATE
Ran local tests locally on an arm machine and they all passed

[Gmerold]

LGTM.