Conversion of png file with transparent background into avif results in black background

[melkishengue]

Converting a png with a transparent background into avif results in a black background as you can see with the following files:

Original file:

Converted file: input-qoD.avif.zip

Had to zip the converted file because github does not support avif file uploading.

For the conversion:

avif.Encode(writer, img, nil)