Refactor lib/utils/checkInvalidCLIOptions.js (#6003)

This small refactoring aims to make `buildAllowedOptions()` more readable.

The number of loops is doubled (`Object.keys()` and `Object.values()`),
but it will not degrade performance since `allowedOptions` is a small array.

lib/utils/checkInvalidCLIOptions.js

@@ -9,17 +9,14 @@ const { red, cyan } = require('picocolors');
  * @return {string[]}
  */
 const buildAllowedOptions = (allowedOptions) => {
-	let options = Object.keys(allowedOptions);
-
-	options = options.reduce((opts, opt) => {
-		const alias = allowedOptions[opt].alias;
+	const options = Object.keys(allowedOptions);
 
+	for (const { alias } of Object.values(allowedOptions)) {
 		if (alias) {
-			opts.push(alias);
+			options.push(alias);
 		}
+	}
 
-		return opts;
-	}, options);
 	options.sort();
 
 	return options;