Update changelog for v2.1.39

Author: github-actions[bot]

CHANGELOG.md

@@ -1,6 +1,6 @@
 # CodeQL Action Changelog
 
-## [UNRELEASED]
+## 2.1.39 - 18 Jan 2023
 
 - CodeQL Action v1 is now deprecated, and is no longer updated or supported. For better performance, improved security, and new features, upgrade to v2. For more information, see [this changelog post](https://github.blog/changelog/2023-01-18-code-scanning-codeql-action-v1-is-now-deprecated/). [#1467](https://github.com/github/codeql-action/pull/1466)
 - Python automatic dependency installation will no longer fail for projects using Poetry that specify `virtualenvs.options.no-pip = true` in their `poetry.toml`. [#1431](https://github.com/github/codeql-action/pull/1431)