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

https://github.com/Duncaen/void-packages firefox-115
https://github.com/void-linux/void-packages/pull/44848

icu-73.2, firefox-115.0
[ci skip]

A patch file from https://github.com/void-linux/void-packages/pull/44848.patch is attached