There's a closed pull request on the void-packages repository

etesync-dav upgrade to 0.18.1, new package radicale3
https://github.com/void-linux/void-packages/pull/22810

Description:
This upgrades etesync-dav to 0.18.1, which requires radicale 3.x. So there's also a commit adding radicale3, and making it conflict with radicale and radicale2.