fix: Audio Preview: Sync clock to make short files play properly on Win

Clock sync seems to be required on Windows to ensure that also short audio files are played back properly.

Earlier, it turned out that syncing the pipeline (for a single stream only in the audio preview case) could cause some delay when starting a new playback. Testing today on openSUSE TW I could however no longer reproduce this issue. Since I haven't tested it on other distributions and not-syncing doesn't seem to cause any downsides, this patch leaves the setting as it was before on Linux.

Fixes: #11368 (closed)