The `os.userInfo()` call might throw on POSIX if there is no
user info for the current `uid`. This might happen, if the docker
is launched like this:
```
docker run --rm -u 1234:1234 -it mcr.microsoft.com/playwright:v1.32.0 node -e 'console.log(os.userInfo().username)'
```
So instead of using `os.userInfo()`, rely on effective user id.
Fixes https://github.com/microsoft/playwright/issues/22721
3b2d247c74