fix(kubectx): don't error on missing k8s context (#10675)

plugins/kubectx/kubectx.plugin.zsh

@@ -3,7 +3,9 @@ typeset -g -A kubectx_mapping
 function kubectx_prompt_info() {
   (( $+commands[kubectl] )) || return
 
-  local current_ctx=$(kubectl config current-context)
+  local current_ctx=$(kubectl config current-context 2> /dev/null)
+
+  [[ -n "$current_ctx" ]] || return
 
   # use value in associative array if it exists
   # otherwise fall back to the context name