sysutils/lnav: Update to 0.12.3

ChangeLog:
https://github.com/tstack/lnav/compare/0.12.3-beta2-62-g1bef9f04...v0.12.3
https://github.com/tstack/lnav/releases/tag/v0.12.3

PR: 282885
MFH: 2024Q4
(cherry picked from commit 0ac4d265640645ba45cc5d9f388fb88a779a27f3)