build: remove dev-infra @angular/build-tooling package

With the migration to use `rules_js` with Bazel,
this package should no longer be needed.

Author: clydin

package.json

@@ -48,7 +48,6 @@
   "devDependencies": {
     "@ampproject/remapping": "2.3.0",
     "@angular/animations": "20.0.0-next.1",
-    "@angular/build-tooling": "https://github.com/angular/dev-infra-private-build-tooling-builds.git#d4727212a9d0f7eb63ae3116d73c769d9bd0bdc1",
     "@angular/cdk": "20.0.0-next.0",
     "@angular/common": "20.0.0-next.1",
     "@angular/compiler": "20.0.0-next.1",