[BUG] ffmpeg missing when only installing one browser on Linux

[matrey]

I was only interested in chromium so I used playwright install chromium
This only created ~/.cache/ms-playwright/chromium-854489/

But then when I tried to get a video trace, it failed with:

playwright._impl._api_types.Error: Failed to launch browser: Error: spawn ~/.cache/ms-playwright/ffmpeg-1005/ffmpeg-linux ENOENT

playwright install ffmpeg does not work:

Invalid browser name: 'ffmpeg'. Expecting 'chromium', 'firefox' or 'webkit'.

Note that running playwright install does download ffmpeg, the issue only exists when you just want 1 browser.

Downloading webkit v1438 - 77.2 Mb [====================] 100% 0.0s 
webkit v1438 downloaded to ~/.cache/ms-playwright/webkit-1438
Downloading firefox v1234 - 72.2 Mb [====================] 100% 0.0s 
firefox v1234 downloaded to ~/.cache/ms-playwright/firefox-1234
Downloading ffmpeg v1005 - 2.6 Mb [====================] 100% 0.0s 
ffmpeg v1005 downloaded to ~/.cache/ms-playwright/ffmpeg-1005