net/krill: Update to 0.15.1

Version 0.15.1 'Contains Adult Language'

Bug fixes

• Fixed a bug introduced in 0.15.0 where CAs do to not clear fulfilled certification requests causing them to re-request a certificate every time they contact their parent. ([#1345])

Other changes

• Updated dependencies.

Release Announcement: https://nlnetlabs.nl/news/2026/Jan/19/krill-0.15.1-released/
Changelog: https://github.com/NLnetLabs/krill/releases/tag/v0.15.1

PR: 292605
Reported by: Jaap Akkerhuis <jaap@NLnetLabs.nl> (maintainer)