removed unnecessary file stacking rule

This rule did not check for a parttype. According to the documantation (https://jellyfin.org/docs/general/server/media/shows/#episodes-split-across-multiple-parts) there should be one.

Emby.Naming/Common/NamingOptions.cs

@@ -141,8 +141,7 @@ namespace Emby.Naming.Common
             VideoFileStackingRules = new[]
             {
                 new FileStackRule(@"^(?<filename>.*?)(?:(?<=[\]\)\}])|[ _.-]+)[\(\[]?(?<parttype>cd|dvd|part|pt|dis[ck])[ _.-]*(?<number>[0-9]+)[\)\]]?(?:\.[^.]+)?$", true),
-                new FileStackRule(@"^(?<filename>.*?)(?:(?<=[\]\)\}])|[ _.-]+)[\(\[]?(?<parttype>cd|dvd|part|pt|dis[ck])[ _.-]*(?<number>[a-d])[\)\]]?(?:\.[^.]+)?$", false),
-                new FileStackRule(@"^(?<filename>.*?)(?:(?<=[\]\)\}])|[ _.-]?)(?<number>[a-d])(?:\.[^.]+)?$", false)
+                new FileStackRule(@"^(?<filename>.*?)(?:(?<=[\]\)\}])|[ _.-]+)[\(\[]?(?<parttype>cd|dvd|part|pt|dis[ck])[ _.-]*(?<number>[a-d])[\)\]]?(?:\.[^.]+)?$", false)
             };
 
             CleanDateTimes = new[]