We have a replacement Cronie. Vixie-cron is no longer actively developed nor maintained. Fork project Cronie is the most prevalent one.
I am going to revert this as patch for Turris OS 4.0.
Companion MR: https://gitlab.labs.nic.cz/turris/turris-build/merge_requests/25
Implements: https://gitlab.labs.nic.cz/turris/turris-os-packages/issues/459