Remove minikube support for legacy 32-bit architectures #22378
Description
Kubernetes dropped support for arm (armv7) in version 1.27, released in 2023.
https://kubernetes.io/blog/2023/04/11/kubernetes-v1-27-release/
Raspberry Pi OS (raspbian) changed to the 64-bit OS version by default, in 2022.
https://www.raspberrypi.com/news/raspberry-pi-os-64-bit/
So it is no longer needed to build minikube for any arm32, only for arm64.
We can also remove the experimental client-only builds for x86 and armv6.
(these were only used to interact with a remote cluster using the ssh driver)
The mainframe targets still remain upstream, but they're less supported...
(the deal is that the binaries are built for the architectures, but not tested)
OBS is making packages for architectures: amd64, arm64, ppc64le, s390x