Add changelog note

Author: github-actions[bot]

Diff for: CHANGELOG.md

@@ -7,6 +7,7 @@ Note that the only difference between `v2` and `v3` of the CodeQL Action is the
 ## [UNRELEASED]
 
 - Bump the minimum CodeQL bundle version to 2.14.6. [#2549](https://github.com/github/codeql-action/pull/2549)
+- Update default CodeQL bundle version to 2.19.2. [#2552](https://github.com/github/codeql-action/pull/2552)
 
 ## 3.26.13 - 14 Oct 2024