Raspberry Pi OS

Hacks

Set static (manual) IP

nmcli con modify Wired\ connection\ 1 ipv4.addresses 192.168.0.2/24
nmcli con modify Wired\ connection\ 1 ipv4.gateway 192.168.0.1
nmcli con modify Wired\ connection\ 1 ipv4.dns 8.8.8.8
nmcli con modify Wired\ connection\ 1 ipv4.method manual
nmcli connection up Wired\ connection\ 1

... sets up a static (manual) IP for IPv4

Disable IPv6

nmcli con modify Wired\ connection\ 1 ipv6.method disabled
nmcli connection up Wired\ connection\ 1

... disables IPv6 for the given connection

Disable Bluetooth and WiFi

systemctl disable bluetooth
systemctl disable wpa_supplicant.service
systemctl disable hciuart.service

and then we put

dtoverlay=disable-wifi
dtoverlay=disable-bt

... in /boot/firmware/config.txt ... disables WiFi and BT