Prepare release v324 (#1991)

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]
 
+
+## [v324] - 2025-12-09
+
 - The build now errors if an existing Python virtual environment is found in the build directory at `.venv/` or `venv/`. This replaces the warning displayed since September 2025. ([#1990](https://github.com/heroku/heroku-buildpack-python/pull/1990))
 - Stopped adding the current working directory to `PATH`. ([#1987](https://github.com/heroku/heroku-buildpack-python/pull/1987))
 
@@ -1424,7 +1427,8 @@ 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/v323...main
+[unreleased]: https://github.com/heroku/heroku-buildpack-python/compare/v324...main
+[v324]: https://github.com/heroku/heroku-buildpack-python/compare/v323...v324
 [v323]: https://github.com/heroku/heroku-buildpack-python/compare/v322...v323
 [v322]: https://github.com/heroku/heroku-buildpack-python/compare/v321...v322
 [v321]: https://github.com/heroku/heroku-buildpack-python/compare/v320...v321