There's a closed pull request on the void-packages repository

ipv6calc: update to 3.1.0
https://github.com/void-linux/void-packages/pull/30962

Description:
#### Have the results of the proposed changes been tested?
- [ x] I use the packages affected by the proposed changes on a regular basis and confirm this PR works for me
- [ ] I generally don't use the affected packages but briefly tested this PR