multimedia/gstreamer1-libav: Update to 1.22.1

Fixes build with FFmpeg 6.0

Changelog: https://gitlab.freedesktop.org/gstreamer/gstreamer/-/blob/1.22.1/subprojects/gst-libav/NEWS

PR: 270255
Reviewed by: arrowd
Tested by: jbeich, George Mitchell <george@m5p.com>
Approved by: portmgr (maintainer timeout, 1 month)