There is a new pull request by pbui against master on the void-packages repository

https://github.com/pbui/void-packages python3-Telethon
https://github.com/void-linux/void-packages/pull/27744

python3-Telethon: update to 1.19.0.
Add checkdepends.

A patch file from https://github.com/void-linux/void-packages/pull/27744.patch is attached