Garm v4 plan

[mlajkim]

Garm v4 without v1beta1 supported

• As the same: https://github.com/AthenZ/garm/pull/28/files

SET_CAP REMOVED

We should delete this line because it really depends on the environment you build your image.
For example, if you disable docker_buildkit, the setcap won't work and your garm image will not be able to use the privileged port (or 1~1024)

But again, such changes will make the users of garm to have their garm image settings with like this:

securityContext:
  sysctls:
  - name: net.ipv4.ip_unprivileged_port_start
    value: "1"         

and this is a destructive changes so we would like to bring it when it becomes v4.

https://github.com/AthenZ/garm/blob/master/Dockerfile#L35-L36