Added darwin arm64 krew

[kimsondrup]

Fixing issue installing the plugin with krew on M1 and M2 based Macs

> uname -ms
Darwin arm64
> kubectl krew install aks
Updated the local copy of plugin index.
Installing plugin: aks
W0926 15:18:56.304641   54611 install.go:164] failed to install plugin "aks": plugin "aks" does not offer installation for this platform
failed to install some plugins: [aks]: plugin "aks" does not offer installation for this platform

[mqasimsarfraz]

LGTM! Thanks for the contribution!

[mqasimsarfraz]

@kim-sondrup darwin arm64 should be part of of the next release we publish on krew but in case you wanted to use the plugin, the current release already published the darwin arm64 variant!