benchmark: update number of iterations for util.inspect

PR-URL: #50651
Refs: #50571
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Vinícius Lourenço Claro Cardoso <contact@viniciusl.com.br>

Author: kylo5aby

benchmark/util/inspect.js

@@ -9,7 +9,7 @@ const opts = {
   none: undefined,
 };
 const bench = common.createBenchmark(main, {
-  n: [2e4],
+  n: [8e4],
   method: [
     'Object',
     'Object_empty',