Remove references to master node-role label and taints/tolerations

[brandond]

K3s tracking issue:

• Remove references to master node-role label and taints/tolerations k3s-io/k3s#11117

Upstream Kubernetes started deprecating this in v1.20 and finally removed it completely in v1.26:
https:/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/2067-rename-master-label-taint/README.md

The Kubernetes project is moving away from wording that is considered offensive. A new working group WG Naming was created to track this work, and the word "master" was declared as offensive. A proposal was formalized for replacing the word "master" with "control plane". This means it should be removed from source code, documentation, and user-facing configuration from Kubernetes and its sub-projects.

We should remove any references to master for v1.32+. Existing nodes can keep the label, but new nodes running v1.32 or newer should not have it added automatically. No packaged components should use the label, taint, or toleration.