feat: add k3s to renovaterc

.renovaterc

@@ -2,6 +2,13 @@
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
   "extends": ["local>infrastructure/renovate-config"],
   "regexManagers": [
+    {
+      "description": "k3s",
+      "fileMatch": ["pb_install\\.yml"],
+      "matchStrings": ["\\s+INSTALL_K3S_CHANNEL:\\s(?<currentValue>.*)"],
+      "depNameTemplate": "k3s-io/k3s",
+      "datasourceTemplate": "github-releases"
+    },
     {
       "description": "ArgoCD",
       "fileMatch": ["argocd-init\\.yml$"],