* kubeadm: do not ignore preflight errors blindly
The "ignoring all errors" seems to date back to the inception of the
kubeadm support (it was --skip-preflight-check before).
This can mask real errors and prevent users from seeing them.
Do not ignore any errors by default and make the set of ignored errors
configurable.
* download/kubeadm: remove redundant task
The mode is already set by the previous `copy` task.
* Validate kubeadm configs
This should help to fail early when we have invalid kubeadm configs (from
a kubespray bug or a misconfiguration).
* kubeadm-upgrade: remove unnecessary bool cast
* Convert kubeadm join discovery timeout to v1beta4 config
* CI: Ignore kubeadm:Mem errors on some setup.
Currently there is not much difference between the files, if there are more changes in the future,
please use different files to distinguish them (you can use the kubeadm_config_api_version variable)
Signed-off-by: ChengHao Yang <17496418+tico88612@users.noreply.github.com>