LibWebRTCVPXVideoEncoder does not need to set the decoder codecType
<rdar://problem/101539998>
Pull request: https://github.com/WebKit/WebKit/pull/5751
Committed 256006@main (09b196a141a8): <https://commits.webkit.org/256006@main> Reviewed commits have been landed. Closing PR #5751 and removing active labels.