refactor(@angular-devkit/build-angular): remove unused imported symbol

This commit removes an unused imported symbol.

(cherry picked from commit 2fb4b24)

packages/angular_devkit/build_angular/src/tools/esbuild/bundler-context.ts

@@ -18,7 +18,7 @@ import {
   context,
 } from 'esbuild';
 import assert from 'node:assert';
-import { basename, dirname, extname, join, relative } from 'node:path';
+import { basename, extname, join, relative } from 'node:path';
 import { LoadResultCache, MemoryLoadResultCache } from './load-result-cache';
 import { convertOutputFile } from './utils';