Cleanup partial class declarations.

Author: dlemstra

src/Magick.NET/Native/MagickImage.cs

@@ -18,7 +18,7 @@
 namespace ImageMagick;
 
 /// <content />
-public partial class MagickImage : IDisposable
+public partial class MagickImage
 {
     private NativeMagickImage _nativeInstance;
 
@@ -875,5 +875,8 @@ private unsafe sealed partial class NativeMagickImage : NativeInstance, INativeM
 
         [Throws]
         public partial void WriteStream(IMagickSettings<QuantumType>? settings, ReadWriteStreamDelegate? writer, SeekStreamDelegate? seeker, TellStreamDelegate? teller, ReadWriteStreamDelegate? reader, void* data);
+
+        void INativeMagickImage.Dispose(IntPtr instance)
+            => Dispose(instance);
     }
 }

src/Magick.NET/net8.0/MagickImage.cs

@@ -19,7 +19,7 @@
 namespace ImageMagick;
 
 /// <content/>
-public sealed partial class MagickImage
+public partial class MagickImage
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="MagickImage"/> class.