chore(deps): update rancher/kubectl docker tag to v1.31.8

Author: renovate-rancher[bot]

chart/values.yaml

@@ -45,7 +45,7 @@ global:
     clusterName: ""
   kubectl:
     repository: rancher/kubectl
-    tag: v1.31.7
+    tag: v1.31.8
 
 alerts:
   enabled: false