Add support for AVIF uploads (#19647)

app/models/media_attachment.rb

@@ -44,7 +44,7 @@ class MediaAttachment < ApplicationRecord
   MAX_VIDEO_MATRIX_LIMIT = 2_304_000 # 1920x1200px
   MAX_VIDEO_FRAME_RATE   = 60
 
-  IMAGE_FILE_EXTENSIONS = %w(.jpg .jpeg .png .gif .webp .heic .heif).freeze
+  IMAGE_FILE_EXTENSIONS = %w(.jpg .jpeg .png .gif .webp .heic .heif .avif).freeze
   VIDEO_FILE_EXTENSIONS = %w(.webm .mp4 .m4v .mov).freeze
   AUDIO_FILE_EXTENSIONS = %w(.ogg .oga .mp3 .wav .flac .opus .aac .m4a .3gp .wma).freeze
 
@@ -55,7 +55,7 @@ class MediaAttachment < ApplicationRecord
     small
   ).freeze
 
-  IMAGE_MIME_TYPES             = %w(image/jpeg image/png image/gif image/heic image/heif image/webp).freeze
+  IMAGE_MIME_TYPES             = %w(image/jpeg image/png image/gif image/heic image/heif image/webp image/avif).freeze
   IMAGE_CONVERTIBLE_MIME_TYPES = %w(image/heic image/heif).freeze
   VIDEO_MIME_TYPES             = %w(video/webm video/mp4 video/quicktime video/ogg).freeze
   VIDEO_CONVERTIBLE_MIME_TYPES = %w(video/webm video/quicktime).freeze