Fix tests for RemotePlayback API

[Elchi3]

As described in mdn/browser-compat-data#21486 Chrome Desktop only shipped this API in v121. I can confirm this with manual testing. The collector tests need to be made better.

Maybe it should test for the NotSupportedError?
The following demo works for me on Safari Desktop 17.3 but doesn't work on Chrome 120. Maybe it can be inspiration for better collector tests: https://beaufortfrancois.github.io/sandbox/media/remote-playback.html