This Post saved my A** because i walked into the same Pihole removal trap.
In the end, i downloaded:
ifupdown_0.8.36_arm64.deb
iproute2_5.10.0-4_arm64.deb
libdns-export1110_9.11.19+dfsg-2.1_arm64.deb
libisc-export1105_9.11.19+dfsg-2.1_arm64.deb
libbpf0_0.3-2_arm64.deb
isc-dhcp-client_4.4.1-2.3+deb11u2_arm64.deb
from here:
http://ftp.debian.org/debian/pool/main/i/
and
https://packages.debian.org/search?suite=default§ion=all&arch=any&searchon=names&keywords=libdns
as Stable. Moved anything into a Folder on a USB Drive. Mounted that drive on my Dietpi, searched the Folder and run
dpkg -i *.deb
followed by a reboot.
Thank God, everything is working again.