Updates comment for --incompatible_disable_native_repo_rules.

Tried to enable this and found one missing `load` statement in the external example. However this option appears to just be broken with `--enable_bzlmod` as it triggers an error in a non-existant `WORKSPACE` file, even if the actual `WORKSPACE` file is empty. I filed bazelbuild/bazel#23206, as it appears to be a core Bazel bug. `--enable_bzlmod` breaks a bunch of things here and I haven't had time to properly look into it, so I think it's best to just leave `--incompatible_disable_native_repo_rules` off for now.

examples/external/WORKSPACE.bazel

@@ -1,6 +1,7 @@
 workspace(name = "external")
 
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+load("@bazel_tools//tools/build_defs/repo:local.bzl", "local_repository")
 
 http_archive(
     name = "aspect_bazel_lib",

tools/bazelrc/incompatible.bazelrc

@@ -19,7 +19,8 @@ common --incompatible_check_testonly_for_output_files
 common --incompatible_default_to_explicit_init_py
 common --incompatible_disable_native_android_rules
 
-# Breaks `@rules_prerender` `WORKSPACE` file.
+# Breaks with `--noenable_bzlmod`.
+# https://github.com/bazelbuild/bazel/issues/23206
 # common --incompatible_disable_native_repo_rules
 
 common --incompatible_disable_non_executable_java_binary