Release: update changelog for 10.4.12 (#96108)

* Update changelog

* Update changelog

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Andreas Christou <andreas.christou@grafana.com>

CHANGELOG.md

@@ -1,3 +1,12 @@
+<!-- 10.4.12 START -->
+
+# 10.4.12 (2024-11-08)
+
+### Bug fixes
+
+- **Alerting:** Make context deadline on AlertNG service startup configurable [#96058](https://github.com/grafana/grafana/pull/96058), [@fayzal-g](https://github.com/fayzal-g)
+
+<!-- 10.4.12 END -->
 <!-- 11.3.0 START -->
 
 # 11.3.0 (2024-10-22)