Migration to a new, bigger server is almost done, all the services work from the new one already.
A new Sparky repository public key has been generated so manually intervention is required!
Users of all Sparky versions/editions have to install the new public key as follows:
wget -O - https://repo.sparkylinux.org/sparky.gpg.key | sudo apt-key add -
Then update the package list to check does it work:
sudo apt update