fix: disable metrics and prompts in buildx config

Author: reingart

integration/testdata/buildx/config

@@ -2,8 +2,10 @@ global:
   cache-tag: cache
   buildx-builder: buildkit
   survey:
+    disable-prompt: true
     last-prompted: "2025-01-19T21:32:47Z"
-  collect-metrics: true
+  collect-metrics: false
+  update-check: false
   update:
     last-prompted: "2025-01-19T23:10:47Z"
 kubeContexts: []