mark DangerousGetPinnableReferenceToPixelBuffer() obsolete

src/ImageSharp/Advanced/AdvancedImageExtensions.cs

@@ -127,6 +127,7 @@ namespace SixLabors.ImageSharp.Advanced
         /// <typeparam name="TPixel">The Pixel format.</typeparam>
         /// <param name="source">The source image frame</param>
         /// <returns>A pinnable reference the first root of the pixel buffer.</returns>
+        [Obsolete("This method will be removed in our next release! Please use MemoryMarshal.GetReference(source.GetPixelSpan())!")]
         public static ref TPixel DangerousGetPinnableReferenceToPixelBuffer<TPixel>(this ImageFrame<TPixel> source)
             where TPixel : struct, IPixel<TPixel>
             => ref DangerousGetPinnableReferenceToPixelBuffer((IPixelSource<TPixel>)source);
@@ -139,6 +140,7 @@ namespace SixLabors.ImageSharp.Advanced
         /// <typeparam name="TPixel">The Pixel format.</typeparam>
         /// <param name="source">The source image</param>
         /// <returns>A pinnable reference the first root of the pixel buffer.</returns>
+        [Obsolete("This method will be removed in our next release! Please use MemoryMarshal.GetReference(source.GetPixelSpan())!")]
         public static ref TPixel DangerousGetPinnableReferenceToPixelBuffer<TPixel>(this Image<TPixel> source)
             where TPixel : struct, IPixel<TPixel>
             => ref source.Frames.RootFrame.DangerousGetPinnableReferenceToPixelBuffer();

tests/ImageSharp.Tests/Advanced/AdvancedImageExtensionsTests.cs

@@ -151,6 +151,8 @@ namespace SixLabors.ImageSharp.Tests.Advanced
             }
         }
 
+        #pragma warning disable 0618
+
         [Theory]
         [WithTestPatternImages(131, 127, PixelTypes.Rgba32 | PixelTypes.Bgr24)]
         public unsafe void DangerousGetPinnableReference_CopyToBuffer<TPixel>(TestImageProvider<TPixel> provider)