Previously, we closed pages one by one before closing the browser when
shutting down the persistent context. This logic was introduced in
https://github.com/microsoft/playwright/pull/4040 to properly finish
video recordings in persistent context.
Such a process makes it unnecessary brittle to close the persistent
context. For example, Chromium headless is sometimes unable to close the
last persistent page for unknown reasons.
Instead, we can just stop video recordings manually and close the
browser right away.
Fixes#18229.
As of July 14, 2022, Safari Technoly Preview returns the following:
```
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.0 Safari/605.1.15
```