refactor: remove old compiler options (#14891)

DEPRECATION:
- `CompilerOptions.debug` has no effect any more, as the compiler
  always produces the same code independent of debug mode.

tools/public_api_guard/core/typings/core.d.ts

@@ -205,7 +205,7 @@ export declare abstract class CompilerFactory {
 
 /** @experimental */
 export declare type CompilerOptions = {
-    useDebug?: boolean;
+    /** @deprecated */ useDebug?: boolean;
     useJit?: boolean;
     defaultEncapsulation?: ViewEncapsulation;
     providers?: any[];