Doxxing means sharing people's relevant personal details that you gained without the targets consent.
In the case of malicious scammers, doxxing them so they can be cut off from other code repositories seems less like "vigilante justice" and more like "a public responsibility."
I can't believe it wasn't obvious, but that's the part which implies vigilante justice.
From Wikipedia[0]:
A vigilante is a civilian or organization acting in a law enforcement capacity (or in the pursuit of self-perceived justice) without legal authority.
Doxing has a very specific meaning and it directly implies taking matters into your own hands, aka vigilante.
[0] https://en.m.wikipedia.org/wiki/Vigilante