[C#] Remove superfluous semicolon in C# structs (#6791)

Aims to resolve #6788

-Remove superfluous semicolon in C# structs

tests/union_vector/Attacker.cs

@@ -46,7 +46,7 @@ public struct Attacker : IFlatbufferObject
       builder,
       _o.SwordAttackDamage);
   }
-};
+}
 
 public class AttackerT
 {

tests/union_vector/BookReader.cs

@@ -35,7 +35,7 @@ public struct BookReader : IFlatbufferObject
       builder,
       _o.BooksRead);
   }
-};
+}
 
 public class BookReaderT
 {

tests/union_vector/Movie.cs

@@ -148,7 +148,7 @@ public struct Movie : IFlatbufferObject
       _characters_type,
       _characters);
   }
-};
+}
 
 public class MovieT
 {

tests/union_vector/Rapunzel.cs

@@ -35,7 +35,7 @@ public struct Rapunzel : IFlatbufferObject
       builder,
       _o.HairLength);
   }
-};
+}
 
 public class RapunzelT
 {