benchmark: update iterations in benchmark/util/normalize-encoding.js

Fixes: https://github.com/nodejs/node/issues/50571
PR-URL: https://github.com/nodejs/node/pull/50934
Refs: https://github.com/nodejs/node/issues/50571
Reviewed-By: Vinícius Lourenço Claro Cardoso <contact@viniciusl.com.br>

benchmark/util/normalize-encoding.js

@@ -21,7 +21,7 @@ const inputs = [
 
 const bench = common.createBenchmark(main, {
   input: inputs.concat(Object.keys(groupedInputs)),
-  n: [1e5],
+  n: [1e6],
 }, {
   flags: '--expose-internals',
 });