fix: emqx_utils is just a library, so 'load' is enough

Co-authored-by: Thales Macedo Garitezi <thalesmg@gmail.com>

mix.exs

@@ -303,7 +303,7 @@ defmodule EMQXUmbrella.MixProject do
         tools: :load,
         covertool: :load,
         system_monitor: :load,
-        emqx_utils: :permanent,
+        emqx_utils: :load,
         emqx_http_lib: :permanent,
         emqx_resource: :permanent,
         emqx_connector: :permanent,

rebar.config.erl

@@ -391,7 +391,7 @@ relx_apps(ReleaseType, Edition) ->
             {covertool, load},
             % started by emqx_machine
             {system_monitor, load},
-            emqx_utils,
+            {emqx_utils, load},
             emqx_http_lib,
             emqx_resource,
             emqx_connector,