Refactor to remove Number.isInteger polyfill (#5302)

We will no longer need the polyfill on the next major release (v14).

lib/utils/isNonNegativeInteger.js

@@ -1,17 +1,8 @@
 'use strict';
 
-// TODO: We need this polyfill because of the support of Node 10.
-//       When we will drop Node 10, please remove this polyfill.
-//       See <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isInteger>
-const isInteger =
-	Number.isInteger ||
-	function (value) {
-		return typeof value === 'number' && isFinite(value) && Math.floor(value) === value;
-	};
-
 /**
  * @param {unknown} value
  */
-module.exports = function (value) {
-	return isInteger(value) && typeof value === 'number' && value >= 0;
+module.exports = function isNonNegativeInteger(value) {
+	return Number.isInteger(value) && typeof value === 'number' && value >= 0;
 };