A separate process is `spawnSync`'ed on process exit to cleanup
temporary directories, introduced in #13769 that followed up after
#13343.
A separate process might stall for various fs-related issues, which
prevents the original process from exiting.
With the recent changes, we always gracefully close and cleanup after
all launched executables before calling `process.exit()`, and so it
should only be possible to leave temp directories when using Playwright
and calling `process.exit()` programmatically without closing browsers.
We can now drop the extra process and rely on `rimraf.sync` for
last-resort cleanup in these rare circumstances.
This is a speculative fix to leftover tmp directories.
When users issues SIGINT twice, we enter `gracefullyClose()`
twice, and shortcut the second time. It turns out, we do
not wait for directories removal.
Note: it is unknown how often we reach this codepath in practice.
