build: remove references to tsc-wrapped (#19298)

With this commit `ngc` is used instead of `tsc-wrapped` for
collecting metadata and tsickle rewriting and `tsc-wrapped`
is removed from the repository.

`@angular/tsc-wrapped@5` is now deprecated and is no longer
used, updated, or maintained as part as of Angular 5.x.x.

`@angular/tsc-wrapped@4` is still maintained and required by
Angular 4.x.x and will be maintained as long as 4.x.x is in
LTS.

PR Close #19298

packages/core/testing/tsconfig-build.json

@@ -18,7 +18,8 @@
   ],
 
   "angularCompilerOptions": {
-    "strictMetadataEmit": true,
+    "strictMetadataEmit": false,
+    "skipTemplateCodegen": true,
     "flatModuleOutFile": "testing.js",
     "flatModuleId": "@angular/core/testing"
   }

packages/core/tsconfig-build.json

@@ -5,7 +5,8 @@
     "baseUrl": ".",
     "rootDir": ".",
     "paths": {
-      "rxjs/*": ["../../node_modules/rxjs/*"]
+      "rxjs/*": ["../../node_modules/rxjs/*"],
+      "@angular/core": ["."]
     },
     "outDir": "../../dist/packages/core"
   },
@@ -18,7 +19,8 @@
 
   "angularCompilerOptions": {
     "annotateForClosureCompiler": true,
-    "strictMetadataEmit": true,
+    "strictMetadataEmit": false,
+    "skipTemplateCodegen": true,
     "flatModuleOutFile": "core.js",
     "flatModuleId": "@angular/core"
   }