build: remove unused rollup.config.js files (#28646)

Since we build and publish the individual packages
using Bazel and `build.sh` has been removed, we can
safely remove the `rollup.config.js` files which are no
longer needed because the `ng_package` bazel rule
automatically handles the rollup settings and globals.

PR Close #28646

packages/language-service/rollup.config.js

@@ -1,72 +0,0 @@
-/**
- * @license
- * Copyright Google Inc. All Rights Reserved.
- *
- * Use of this source code is governed by an MIT-style license that can be
- * found in the LICENSE file at https://angular.io/license
- */
-
-const commonjs = require('rollup-plugin-commonjs');
-const sourcemaps = require('rollup-plugin-sourcemaps');
-const path = require('path');
-const fs = require('fs');
-
-var m = /^\@angular\/((\w|\-)+)(\/(\w|\d|\/|\-)+)?$/;
-var location = normalize('../../dist/packages-dist') + '/';
-var rxjsLocation = normalize('../../node_modules/rxjs');
-var tslibLocation = normalize('../../node_modules/tslib');
-
-var locations = {'compiler-cli': normalize('../../dist/packages') + '/'};
-
-var esm_suffixes = {};
-
-function normalize(fileName) {
-  return path.resolve(__dirname, fileName);
-}
-
-function resolve(id, from) {
-  // console.log('Resolve id:', id, 'from', from)
-  var match = m.exec(id);
-  if (match) {
-    var packageName = match[1];
-    var esm_suffix = esm_suffixes[packageName] || '';
-    var loc = locations[packageName] || location;
-    var r = loc !== location && (loc + esm_suffix + packageName + (match[3] || '/index') + '.js') ||
-        loc + packageName + '/fesm5/' + packageName + '.js';
-    return r;
-  }
-  if (id && (id == 'rxjs' || id.startsWith('rxjs/'))) {
-    return `${rxjsLocation}${id.replace('rxjs', '')}/index.js`;
-  }
-  if (id == 'tslib') {
-    return tslibLocation + '/tslib.es6.js';
-  }
-}
-
-var banner = fs.readFileSync('bundles/banner.js.txt', 'utf8');
-
-module.exports = {
-  entry: '../../dist/packages-dist/language-service/fesm5/language-service.js',
-  dest: '../../dist/packages-dist/language-service/bundles/language-service.umd.js',
-  format: 'amd',
-  amd: {
-      // Don't name this module, causes
-      // Loading the language service caused the following exception: TypeError:
-      // $deferred.modules.map is not a function
-      // id: '@angular/language-service'
-  },
-  moduleName: 'ng.language_service',
-  exports: 'named',
-  external: [
-    'fs',
-    'path',
-    'typescript',
-  ],
-  globals: {
-    'typescript': 'ts',
-    'path': 'path',
-    'fs': 'fs',
-  },
-  banner: banner,
-  plugins: [{resolveId: resolve}, commonjs(), sourcemaps()]
-};