build: Enable codecov AI PR review (#9850)

See:
https://github.com/codecov/vscode/pull/35/files#diff-084bdbbae104c91c8af1a0b632b46b9e797366d5427a2f11aa0332007866af39R2334-R2359

This is undocumented and in alpha, but I figured we should try testing
it out!

Author: AbhiPrasad

codecov.yml

@@ -3,6 +3,11 @@ codecov:
   notify:
     require_ci_to_pass: no
 
+ai_pr_review:
+  enabled: true
+  method: "label"
+  label_name: "ci-codecov-ai-review"
+
 coverage:
   precision: 2
   round: down