chore(deps): update dependency kubeops.cli to v8.0.0-pre.8

Author: renovate[bot]

.config/dotnet-tools.json

@@ -9,7 +9,7 @@
       ]
     },
     "kubeops.cli": {
-      "version": "8.0.0-pre.6",
+      "version": "8.0.0-pre.8",
       "commands": [
         "kubeops"
       ]