Prepare release v279 (#1766)

Co-authored-by: heroku-linguist[bot] <136119646+heroku-linguist[bot]@users.noreply.github.com>

Author: heroku-linguist[bot]

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## [Unreleased]
 
+
+## [v279] - 2025-02-26
+
 - Updated Poetry from 2.0.1 to 2.1.1. ([#1758](https://github.com/heroku/heroku-buildpack-python/pull/1758))
 - Stopped filtering out pip's `Requirement already satisfied:` log lines when installing dependencies. ([#1765](https://github.com/heroku/heroku-buildpack-python/pull/1765))
 - Improved the error messages shown if installing pip/Poetry/Pipenv fails. ([#1764](https://github.com/heroku/heroku-buildpack-python/pull/1764))
@@ -1177,7 +1180,8 @@ Default Python is now latest 2.7.10. Updated pip and Distribute.
 - Setuptools updated to v16.0
 - pip updated to v7.0.1
 
-[unreleased]: https://github.com/heroku/heroku-buildpack-python/compare/v278...main
+[unreleased]: https://github.com/heroku/heroku-buildpack-python/compare/v279...main
+[v279]: https://github.com/heroku/heroku-buildpack-python/compare/v278...v279
 [v278]: https://github.com/heroku/heroku-buildpack-python/compare/v277...v278
 [v277]: https://github.com/heroku/heroku-buildpack-python/compare/v276...v277
 [v276]: https://github.com/heroku/heroku-buildpack-python/compare/v275...v276