Making your Pi-hole host __NOT__ use Pi-hole - Rapbian / Debian (trixie)

NetworkManager.conf

# /etc/NetworkManager/NetworkManager.conf
# Making your Pi-hole host __NOT__ use Pi-hole

# See https://docs.pi-hole.net/main/post-install/#making-your-pi-hole-host-use-pi-hole
# => Disclaimer: it's a bad idea : If your Pi-hole host is using Pi-hole as upstream DNS server and Pi-hole fails, your host 
# loses DNS resolution. This can prevent successful repair attempts, 
# e.g. by pihole -r as it needs a working internet connection.

# Apply the configuration below 

[main]
plugins=ifupdown,keyfile
# the following line prevents NetWorkManager to update resolv.conf
# then "sudo service NetworkManager restart" or reboot
dns=none

[ifupdown]
managed=false