doc: remove "has been known" tentativeness

Remove unnecessary "has been known to" tentativeness from
COLLABORATOR_GUIDE.md. "has been known to" is an awkward replacement for
"can" or "might" or "sometimes does" or "does". Pick the right one and
use it.

PR-URL: https://github.com/nodejs/node/pull/20412


Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>