cad/klayout: Update 0.30.10 => 0.30.12
Release Notes:
https://www.klayout.de/development.html#0.30.12
Changelog:
https://github.com/KLayout/klayout/blob/v0.30.12/Changelog
PR: 299028
Sponsored by: UNIS Labs (vvd, commit patch)
MFH: 2026Q4
(cherry picked from commit bbdf3f9c05267471d7af70f1042da1d761a91ec1)