build: remove skydoc and rules_sass from repository (#42760)

Skydoc is no longer used as `@angular/bazel` is no longer a
public API. The Sass rules were only used in a single place
in the repo where Sass is not really needed and has just been
added by accident most likely. We want to remove the Sass dependency
in preparation for Rules NodeJS v4.x where the Sass rules currently
still use an older version of `@bazel/worker` that is incompatible.

PR Close #42760

integration/bazel/src/hello-world/BUILD.bazel

@@ -1,10 +1,10 @@
-package(default_visibility = ["//visibility:public"])
-
 load("@npm//@bazel/concatjs:index.bzl", "karma_web_test_suite")
 load("@io_bazel_rules_sass//:defs.bzl", "sass_binary")
 load("@npm//@angular/bazel:index.bzl", "ng_package")
 load("//tools:ng_ts_library.bzl", "ng_ts_library")
 
+package(default_visibility = ["//visibility:public"])
+
 sass_binary(
     name = "hello-world-styles",
     src = "hello-world.component.scss",