There is an updated pull request by paper42 against master on the void-packages repository

https://github.com/paper42/void-packages galculator-remove-gtk2
https://github.com/void-linux/void-packages/pull/41443

galculator: remove gtk2 subpackage
@classabbyamp you recently did something similar with a package that had -gtk2 and -gtk3 variant, could you look at this?

A patch file from https://github.com/void-linux/void-packages/pull/41443.patch is attached