docs: Document running via kubeconfig on EKS
docs: Document running via kubeconfig on EKS

We now support using any kubeconfig to run tests, similar to sshconfig.
More steps are required but they are not complex.

Signed-off-by: Ray Bejjani <7f525154e857f3d57a641a83dddc584f42addc6a@isovalent.com>

tklauser/cilium,cilium/cilium,tklauser/cilium,michi-covalent/cilium,cilium-team/cilium,michi-covalent/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,cilium-team/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,tgraf/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium