Kubernetes 1.20 deprecated the node-role.kubernetes.io/master label and replaced it with node-role.kubernetes.io/control-plane, and 1.24 dropped the legacy label entirely. The scheduler-k3s:cluster:add join path still filtered control-plane nodes with master=true, so on any k3s release built from Kubernetes 1.24+ the lookup matched zero nodes and aborted with "no nodes found in the cluster" before the worker could join.
