Replace code using p1_time_compat wrapper with native functions

Since we now require R19, we shouldn't need that anymore.

There are still couple places where p1_time_compat:unique_timestamp() is
used as there is no direct equivalent.

src/elixir_logger_backend.erl

@@ -103,7 +103,7 @@ normalize_pid(Metadata) ->
 
 %% Return timestamp with milliseconds
 timestamp(Time, UTCLog) ->
-    {_, _, Micro} = p1_time_compat:timestamp(),
+    {_, _, Micro} = erlang:timestamp(),
     {Date, {Hours, Minutes, Seconds}} =
         case UTCLog of
             true  -> calendar:now_to_universal_time(Time);