- bump version to 2.9.0
- bump zephyr version to 0.16.9
SDK release notes: https://docs.nordicsemi.com/bundle/ncs-2.9.0/page/nrf/releases_and_maturity/releases/release-notes-2.9.0.html
ZBoss release notes: https://ncsdoc.z6.web.core.windows.net/zboss/3.11.6.0/zboss_release_notes.html#zboss_ncs_release_3_11_6_0
Full Changelog: 2.8.0-20250106...2.9.0-20250106