perf(@angular-devkit/build-angular): disable webpack backwards compatible APIs

See https://github.com/webpack/webpack/releases/tag/v5.62.0 and webpack/webpack#14580 for more context.

Author: alan-agius4

packages/angular_devkit/build_angular/src/webpack/configs/common.ts

@@ -408,6 +408,7 @@ export async function getCommonConfig(wco: WebpackConfigOptions): Promise<Config
       ],
     },
     experiments: {
+      backCompat: false,
       syncWebAssembly: true,
       asyncWebAssembly: true,
     },