Do not read more than buffer.Length for uncompressed tiff

src/ImageSharp/Formats/Tiff/Compression/Decompressors/NoneTiffCompression.cs

@@ -23,6 +23,6 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Compression.Decompresso
         }
 
         /// <inheritdoc/>
-        protected override void Decompress(BufferedReadStream stream, int byteCount, Span<byte> buffer) => _ = stream.Read(buffer, 0, byteCount);
+        protected override void Decompress(BufferedReadStream stream, int byteCount, Span<byte> buffer) => _ = stream.Read(buffer, 0, Math.Min(buffer.Length, byteCount));
     }
 }