Depending on the system load the test 'video_capture_with_tags' may
fail or not. Reason is that 'videotestsrc' may emit a buffer before
the final caps negotiation on the recording pipeline has happened
after dynamic linking.
In that case there would be a caps change and because videorate does
no longer drop old buffers and caps on change but pushes duplicates if
required qtmux will notice a caps change and fail to link.
The problem is a synchronization problem in 'camerabin' which became
obvious with the changed behaviour of 'videorate'.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8579>
