chore(deps): update dependency zod to v4

Author: renovate[bot]

deno.json

@@ -55,7 +55,7 @@
     "@opentelemetry/semantic-conventions": "npm:@opentelemetry/semantic-conventions@^1.39.0",
     "@opentelemetry/sdk-metrics": "npm:@opentelemetry/sdk-metrics@^2.5.1",
     "mongodb": "npm:mongodb@^6.21.0",
-    "zod": "npm:zod@3.25.76"
+    "zod": "npm:zod@4.4.3"
   },
   "tasks": {
     "cache": "deno cache bootstrap.ts",