Remove wrong AV1 codecs string (#1630)

Co-authored-by: Hirokazu Honda <[email protected]>

Author: rosetta-jpn

src/content/getusermedia/record/js/main.js

@@ -74,7 +74,6 @@ function getSupportedMimeTypes() {
     'video/webm;codecs=h264,opus',
     'video/mp4;codecs=h264,aac',
     'video/webm;codecs=av01,opus',
-    'video/webm;codecs=av1,opus', // deprecated, prefer av01.
   ];
   return possibleTypes.filter(mimeType => {
     return MediaRecorder.isTypeSupported(mimeType);