Update Jest config to use ts-jest for schematics

Replaces jest-preset-angular with ts-jest, sets test environment to 'node', and updates transform and moduleFileExtensions. Simplifies configuration for Node-based testing in the schematics package.

npm/ng-packs/packages/schematics/jest.config.ts

@@ -2,22 +2,10 @@
 export default {
   displayName: 'schematics',
   preset: '../../jest.preset.js',
-  setupFilesAfterEnv: ['<rootDir>/src/test-setup.ts'],
-  globals: {},
+  testEnvironment: 'node',
   coverageDirectory: '../../coverage/packages/schematics',
   transform: {
-    '^.+.(ts|mjs|js|html)$': [
-      'jest-preset-angular',
-      {
-        tsconfig: '<rootDir>/tsconfig.spec.json',
-        stringifyContentPathRegex: '\\.(html|svg)$',
-      },
-    ],
+    '^.+\\.[tj]s$': ['ts-jest', { tsconfig: '<rootDir>/tsconfig.spec.json' }],
   },
-  transformIgnorePatterns: ['node_modules/(?!.*.mjs$)'],
-  snapshotSerializers: [
-    'jest-preset-angular/build/serializers/no-ng-attributes',
-    'jest-preset-angular/build/serializers/ng-snapshot',
-    'jest-preset-angular/build/serializers/html-comment',
-  ],
+  moduleFileExtensions: ['ts', 'js', 'html'],
 };