build: update visibility for npm package targets to work with new integration test structure (#44238)

As mentioned in the previous commit, integration tests will be declared
in subpackages of `//integration`. For these tests to still rely on the
NPM packages from `HEAD`, we need to update the visibility.

PR Close #44238

packages/bazel/BUILD.bazel

@@ -26,7 +26,7 @@ pkg_npm(
     tags = ["release-with-framework"],
     # Do not add more to this list.
     # Dependencies on the full npm_package cause long re-builds.
-    visibility = ["//integration:__pkg__"],
+    visibility = ["//integration:__subpackages__"],
     deps = [
         "//packages/bazel/src/api-extractor:lib",
         "//packages/bazel/src/ng_package:lib",