refactor(@angular-devkit/build-optimizer): remove redundant loader-utils dependency

Webpack 5 now provides the `getOptions` loader utility directly on the `LoaderContext` object.

Author: clydin

etc/api/angular_devkit/build_optimizer/src/_golden-api.d.ts

@@ -16,6 +16,7 @@ export default function buildOptimizerLoader(this: {
     };
     cacheable(): void;
     callback(error?: Error | null, content?: string, sourceMap?: unknown): void;
+    getOptions(): unknown;
 }, content: string, previousSourceMap: RawSourceMap): void;
 
 export declare function getPrefixClassesTransformer(): ts.TransformerFactory<ts.SourceFile>;

packages/angular_devkit/build_optimizer/package.json

@@ -9,7 +9,6 @@
     "build-optimizer": "./src/build-optimizer/cli.js"
   },
   "dependencies": {
-    "loader-utils": "2.0.0",
     "source-map": "0.7.3",
     "tslib": "2.2.0",
     "typescript": "4.2.4"

packages/angular_devkit/build_optimizer/src/build-optimizer/webpack-loader.ts

@@ -7,8 +7,6 @@
  */
 import { RawSourceMap } from 'source-map';
 import { sources } from 'webpack';
-const loaderUtils = require('loader-utils');
-
 import { buildOptimizer } from './build-optimizer';
 
 interface BuildOptimizerLoaderOptions {
@@ -26,6 +24,7 @@ export default function buildOptimizerLoader(
     _module: { factoryMeta: { skipBuildOptimizer?: boolean; sideEffectFree?: boolean } };
     cacheable(): void;
     callback(error?: Error | null, content?: string, sourceMap?: unknown): void;
+    getOptions(): unknown;
   },
   content: string,
   previousSourceMap: RawSourceMap,
@@ -43,7 +42,7 @@ export default function buildOptimizerLoader(
     return;
   }
 
-  const options: BuildOptimizerLoaderOptions = loaderUtils.getOptions(this) || {};
+  const options = (this.getOptions() || {}) as BuildOptimizerLoaderOptions;
 
   const boOutput = buildOptimizer({
     content,