Used more specific lock

Rather than piggyback on the build lock when getting project mix
config, use a different lock type.

apps/remote_control/lib/lexical/remote_control/mix.ex

@@ -1,7 +1,6 @@
 defmodule Lexical.RemoteControl.Mix do
   alias Lexical.Project
   alias Lexical.RemoteControl
-  alias Lexical.RemoteControl.Build
 
   def in_project(fun) do
     if RemoteControl.project_node?() do
@@ -11,13 +10,17 @@ defmodule Lexical.RemoteControl.Mix do
     end
   end
 
+  def with_lock(fun) do
+    RemoteControl.with_lock(__MODULE__, fun)
+  end
+
   def in_project(%Project{} = project, fun) do
     # Locking on the build make sure we don't get a conflict on the mix.exs being
     # already defined
 
     old_cwd = File.cwd!()
 
-    Build.with_lock(fn ->
+    with_lock(fn ->
       try do
         Mix.ProjectStack.post_config(prune_code_paths: false)