refactor(@angular-devkit/build-angular): remove unused server builder options

BREAKING CHANGE: options `commonChunk` and `vendorChunk` have been removed from the server builder.

Note: this change only effects direct @angular-devkit/build-angular users and not the application developers as users will be migrated automatically off these options.

Author: alan-agius4

packages/angular_devkit/build_angular/src/server/schema.json

@@ -105,18 +105,6 @@
         }
       ]
     },
-    "vendorChunk": {
-      "type": "boolean",
-      "description": "Use a separate bundle containing only vendor libraries.",
-      "default": true,
-      "x-deprecated": "Since version 9. This option has no effect on server platform."
-    },
-    "commonChunk": {
-      "type": "boolean",
-      "description": "Use a separate bundle containing code used across multiple bundles.",
-      "default": true,
-      "x-deprecated": "Since version 9. This option has no effect on server platform."
-    },
     "deployUrl": {
       "type": "string",
       "description": "URL where files will be deployed."