docs: update changelog before v0.15.2 (#1678)

Signed-off-by: Erez Freiberger <enoodle@gmail.com>

Author: enoodle

CHANGELOG.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Unreleased]
 
+## [v0.15.2] - 2026-06-10
+
 ### Fixed
 - Improved solver performance in some large reclaim scenarios [#1627](https://github.com/kai-scheduler/KAI-Scheduler/pull/1627) [itsomri](https://github.com/itsomri)
 - Grove grouper now sets `minSubGroup` (equal to the number of child SubGroups) instead of `minMember=0` on parent SubGroups generated from `topologyConstraintGroupConfigs` [#1639](https://github.com/kai-scheduler/KAI-Scheduler/issues/1639) [davidLif](https://github.com/davidLif)