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

https://github.com/CameronNemo/void-packages isc-dhcp-license
https://github.com/void-linux/void-packages/pull/24868

dhcp: set license to MPL-2.0
https://gitlab.isc.org/isc-projects/dhcp/-/commit/7512d88b9fb650e3c31fcb255676cdbb89d6c7b6

A patch file from https://github.com/void-linux/void-packages/pull/24868.patch is attached