fix(@schematics/angular): remove setting files tsconfig field with SSR/Server generation

The `files` field within the `tsconfig.app.json` file is no longer used
with the "solution" style tsconfig generated with applications. The SSR
and server schematics no longer need to modify this field since all TS
files within `src` are included by default.

Author: clydin

packages/schematics/angular/server/index.ts

@@ -119,10 +119,6 @@ function updateConfigFileApplicationBuilder(options: ServerOptions): Rule {
 function updateTsConfigFile(tsConfigPath: string): Rule {
   return (host: Tree) => {
     const json = new JSONFile(host, tsConfigPath);
-    const filesPath = ['files'];
-    const files = new Set((json.get(filesPath) as string[] | undefined) ?? []);
-    files.add('src/' + serverMainEntryName);
-    json.modify(filesPath, [...files]);
 
     const typePath = ['compilerOptions', 'types'];
     const types = new Set((json.get(typePath) as string[] | undefined) ?? []);

packages/schematics/angular/server/index_spec.ts

@@ -167,7 +167,6 @@ describe('Server Schematic', () => {
       const filePath = '/projects/bar/tsconfig.app.json';
       const contents = parseJson(tree.readContent(filePath).toString());
       expect(contents.compilerOptions.types).toEqual(['node']);
-      expect(contents.files).toEqual(['src/main.ts', 'src/main.server.ts']);
     });
 
     it(`should add 'provideClientHydration' to the providers list`, async () => {

packages/schematics/angular/ssr/index_spec.ts

@@ -76,7 +76,7 @@ describe('SSR Schematic', () => {
         files: string[];
       };
 
-      expect(files).toEqual(['src/main.ts', 'src/main.server.ts', 'src/server.ts']);
+      expect(files).toContain('src/server.ts');
     });
   });