Correct mobster suffix (#33240)

Correct mob grammar

Content.Server/Speech/EntitySystems/MobsterAccentSystem.cs

@@ -14,7 +14,7 @@ public sealed class MobsterAccentSystem : EntitySystem
     private static readonly Regex RegexUpperAr = new(@"(?<=\w)A[Rr](?=\w)");
     private static readonly Regex RegexFirstWord = new(@"^(\S+)");
     private static readonly Regex RegexLastWord = new(@"(\S+)$");
-
+    private static readonly Regex RegexLastPunctuation = new(@"([.!?]+$)(?!.*[.!?])|(?<![.!?])$");
     [Dependency] private readonly IRobustRandom _random = default!;
     [Dependency] private readonly ReplacementAccentSystem _replacement = default!;
 
@@ -84,7 +84,7 @@ public sealed class MobsterAccentSystem : EntitySystem
             }
             if (lastWordAllCaps)
                 suffix = suffix.ToUpper();
-            msg += suffix;
+            msg = RegexLastPunctuation.Replace(msg, suffix);
         }
 
         return msg;