Kali has updated their version from OpenVAS 9 to GVM 11 just some days ago.
https://pkg.kali.org/news/414155/gvm-1101kali6-migrated-to-kali-rolling/
You have to differentiate between the scanner application (called openvas since GVM 11) and the OpenVAS “framework” which is called GVM now. See Frequently Asked Questions (FAQ) for more details.
Therefore the linked instructions are outdated and invalid now. I guess the tool is called gvm-setup instead of openvas-setup.