KubeKey目前不支持Ubuntu 20.04 Arm 版本

```
root@k8saio:~/kubekey# uname -a
Linux k8saio 5.13.0-41-generic #46~20.04.1-Ubuntu SMP Wed Apr 20 13:20:04 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux
root@k8saio:~/kubekey#
root@k8saio:~/kubekey#
root@k8saio:~/kubekey# ka
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod/ks-installer-5d65c99d54-4df5m 0/1 CrashLoopBackOff 8 21m 10.233.93.12 k8saio
pod/ks-installer-5fd7c856fb-c4x9x 0/1 CrashLoopBackOff 8 18m 10.233.93.13 k8saio

NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
deployment.apps/ks-installer 0/1 1 0 9h installer kubesphere/ks-installer:v3.1.0 app=ks-install,version=v3.1.0

NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
replicaset.apps/ks-installer-5d65c99d54 1 1 0 8h installer kubesphere/ks-installer:v3.1.0 app=ks-install,pod-template-hash=5d65c99d54,version=v3.1.0
replicaset.apps/ks-installer-5fd7c856fb 1 1 0 18m installer kubesphere/ks-installer:v3.1.0 app=ks-install,pod-template-hash=5fd7c856fb,version=v3.1.0

NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
node/k8saio Ready master,worker 10h v1.19.9 10.211.55.4 Ubuntu 20.04.4 LTS 5.13.0-41-generic docker://20.10.8

NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
storageclass.storage.k8s.io/local (default) openebs.io/local Delete WaitForFirstConsumer false 9h
root@k8saio:~/kubekey# kl pod/ks-installer-5d65c99d54-4df5m
exec /shell-operator: exec format error
```

Start by reproducing the reported deployment on Ubuntu 20.04 ARM with the shown Kubernetes and Docker versions, then investigate the ks-installer CrashLoopBackOff and the “exec format error.” Done should clearly establish whether KubeKey supports this platform and, if not, identify the required compatibility change or document the limitation.

Written by the indexing model from the issue text.