build(dialyzer): Remove race_conditions static check

rebar.config

@@ -27,7 +27,7 @@
  ]}.
 
 {dialyzer, [
-    {warnings, [unmatched_returns, error_handling, race_conditions]},
+    {warnings, [unmatched_returns, error_handling]},
     {plt_location, "."},
     {plt_prefix, "emqx_dialyzer"},
     {plt_apps, all_apps},