Add missing GC.SuppressFinalize(this)

src/ImageSharp/Memory/Allocators/Internals/UniformUnmanagedMemoryPool.Buffer{T}.cs

@@ -65,6 +65,7 @@ namespace SixLabors.ImageSharp.Memory.Internals
                 }
 
                 base.Dispose(disposing);
+                GC.SuppressFinalize(this);
             }
         }
     }

src/ImageSharp/Memory/DiscontiguousBuffers/MemoryGroup{T}.Owned.cs

@@ -157,6 +157,8 @@ namespace SixLabors.ImageSharp.Memory
                     {
                         ((UniformUnmanagedMemoryPool.Buffer<T>)memoryOwner).MarkDisposed();
                     }
+
+                    GC.SuppressFinalize(this);
                 }
                 else if (disposing)
                 {