test: remove target in tsconfig.server.json

This causes the tests to fail due to reaching the Bazel stderr bytes limit as a warning is issued for every spec run.

Author: alan-agius4

packages/angular_devkit/build_angular/test/hello-world-app/src/tsconfig.server.json

@@ -2,7 +2,6 @@
   "extends": "./tsconfig.app.json",
   "compilerOptions": {
     "outDir": "../dist-server",
-    "target": "es2016",
     "baseUrl": "./",
     "types": ["@angular/localize"]
   },