posts: remove cropped thumbnails.

app/logical/media_file/image.rb

@@ -92,10 +92,6 @@ class MediaFile::Image < MediaFile
     resize(w, h, size: :force, **options)
   end
 
-  def crop(max_width, max_height, **options)
-    resize(max_width, max_height, crop: :attention, **options)
-  end
-
   def preview_frame
     if is_animated?
       FFmpeg.new(file).smart_video_preview

app/logical/media_file/ugoira.rb

@@ -30,10 +30,6 @@ class MediaFile::Ugoira < MediaFile
     preview_frame.preview(width, height, **options)
   end
 
-  def crop(width, height)
-    preview_frame.crop(width, height)
-  end
-
   def duration
     (frame_delays.sum / 1000.0)
   end

app/logical/media_file/video.rb

@@ -15,10 +15,6 @@ class MediaFile::Video < MediaFile
     preview_frame.preview(max_width, max_height, **options)
   end
 
-  def crop(max_width, max_height)
-    preview_frame.crop(max_width, max_height)
-  end
-
   private
 
   def video