fix(mix): bizarre compilation order bug with `emqx` profile

For some bizarre reason, if the `:apps` key is defined in the `project()` callback in the
root umbrella `mix.exs`, it messes up the compilation order that mix follows when
compiling the project from scratch.

Specifically, in the `emqx` profile, even though `:emqx_utils` is an explicit dependency
of `:emqx_ds_builtin_local`, mix insisted in compiling the latter before the former, and
failing, obviously.  Removing the explicit `:apps` from the project definition solved
this.

🫠

mix.exs

@@ -41,8 +41,6 @@ defmodule EMQXUmbrella.MixProject do
     if new_mix_build?() do
       [
         apps_path: "apps",
-        apps:
-          applications(profile_info.release_type, profile_info.edition_type) |> Keyword.keys(),
         erlc_options: erlc_options(profile_info, version),
         version: version,
         deps: deps(profile_info, version),