In the handbook section 13.2.1. "Preventing Logins" the path to nologin is used inconsistently: The first time the path is given as /sbin/nologin, the other two times as /usr/sbin/nologin. Looking at bug #116758 it should likely be /usr/sbin/nologin in the first instance as well.
A commit references this bug:
Date: Thu Jul 18 11:31:35 UTC 2019
New revision: 53262
Consistent use of /usr/sbin/nologin.