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

https://github.com/ndowens/void-packages gstreamer1
https://github.com/void-linux/void-packages/pull/26411

 gstreamer1: update to 1.18.1
gst1-python version 1.18.1 doesn't support python2 anymore so can not update it

A patch file from https://github.com/void-linux/void-packages/pull/26411.patch is attached