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

https://github.com/zdtcd/void-packages nss-3.46.1
https://github.com/void-linux/void-packages/pull/15686

nspr: update to 4.23 & nss: update to 3.46.1.
Firefox 70.0 requires nss 3.46.1
nss depends on nspr

A patch file from https://github.com/void-linux/void-packages/pull/15686.patch is attached