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

tools/gulp-tasks/lint.js

@@ -16,9 +16,6 @@ module.exports = (gulp) => () => {
         // Ignore node_modules directories
         '!**/node_modules/**',
 
-        // Ignore TypeScript mocks because it's not managed by us
-        '!./tools/@angular/tsc-wrapped/test/typescript.mocks.ts',
-
         // Ignore generated files due to lack of copyright header
         // todo(alfaproject): make generated files lintable
         '!**/*.d.ts',