Add Safari versions for OfflineAudioCompletionEvent API (#12458)
Add Safari versions for OfflineAudioCompletionEvent API (#12458)

This PR adds real values for Safari (Desktop and iOS/iPadOS) for the `OfflineAudioCompletionEvent` API, based upon results from the [mdn-bcd-collector](https://mdn-bcd-collector.appspot.com) project (v3.3.0).

Tests Used: https://mdn-bcd-collector.appspot.com/tests/api/OfflineAudioCompletionEvent
mdn/browser-compat-data,chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data