dev: Using new stopwatch, some cleanup. No functional change

src/NadekoBot/_common/_Extensions/Extensions.cs

@@ -229,10 +229,4 @@ public static class Extensions
     public static IEnumerable<IRole> GetRoles(this IGuildUser user)
         => user.RoleIds.Select(r => user.Guild.GetRole(r)).Where(r => r is not null);
 
-    // todo remove
-    public static void Lap(this Stopwatch sw, string checkpoint)
-    {
-        Log.Information("Checkpoint {CheckPoint}: {Time}ms", checkpoint, sw.Elapsed.TotalMilliseconds);
-        sw.Restart();
-    }
 }