change variable defined identifier let to const

Author: MrKou47

lib/WebpackOptionsApply.js

@@ -201,7 +201,7 @@ class WebpackOptionsApply extends OptionsApply {
 		}
 
 		if (options.output.library || options.output.libraryTarget !== "var") {
-			let LibraryTemplatePlugin = require("./LibraryTemplatePlugin");
+			const LibraryTemplatePlugin = require("./LibraryTemplatePlugin");
 			new LibraryTemplatePlugin(
 				options.output.library,
 				options.output.libraryTarget,
@@ -245,7 +245,7 @@ class WebpackOptionsApply extends OptionsApply {
 						: modern
 							? "\n//# source" + "MappingURL=[url]"
 							: null;
-			let Plugin = evalWrapped
+			const Plugin = evalWrapped
 				? EvalSourceMapDevToolPlugin
 				: SourceMapDevToolPlugin;
 			new Plugin({
@@ -381,7 +381,7 @@ class WebpackOptionsApply extends OptionsApply {
 		new WarnCaseSensitiveModulesPlugin().apply(compiler);
 
 		if (options.cache) {
-			let CachePlugin = require("./CachePlugin");
+			const CachePlugin = require("./CachePlugin");
 			new CachePlugin(
 				typeof options.cache === "object" ? options.cache : null
 			).apply(compiler);