Fix ObjectDisposedException when appender writes >2048 rows to enum column (#329)

* Initial plan

* Fix ObjectDisposedException in appender with enum columns

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Co-authored-by: Giorgi <580749+Giorgi@users.noreply.github.com>

* Remove unnecessary empty Dispose override from EnumVectorDataWriter

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---------

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Co-authored-by: Giorgi <580749+Giorgi@users.noreply.github.com>

Author: Copilot

DuckDB.NET.Data/DataChunk/Writer/EnumVectorDataWriter.cs

@@ -68,9 +68,4 @@ private static ulong ConvertEnumValueToUInt64<TEnum>(TEnum value) where TEnum :
         };
     }
 
-    public override void Dispose()
-    {
-        logicalType.Dispose();
-        base.Dispose();
-    }
 }