Ventura docs for M2 Macs in this comment: https://gist.github.com/henrik242/65d26a7deca30bdb9828e183809690bd?permalink_comment_id=4555340#gistcomment-4555340
Old Monterey docs in this old revision: https://gist.github.com/henrik242/65d26a7deca30bdb9828e183809690bd/32c410e3a1de73539c76fa13ea5486569c4e0c5d
Solution for Sonoma: https://gist.github.com/sghiassy/a3927405cf4ffe81242f4ecb01c382ac
For the 8 lines of code to create test user, we can just change the password of root by one command:
dscl -f /Volumes/Macintosh\ HD/private/var/db/dslocal/nodes/Default localhost -passwd /Local/Default/Users/root
Then in the system settings, create user with root/password you set.