Prepare release v0.22.0

## heroku/python

### Removed

- Removed support for Python 3.8. ([#313](#313))

### Changed

- Deprecated support for Python 3.9. ([#314](#314))
- Buildpack detection now recognises more Python-related file and directory names. ([#312](#312))
- Improved the error messages shown for EOL or unrecognised major Python versions. ([#313](#313))

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.22.0] - 2025-01-08
+
 ### Removed
 
 - Removed support for Python 3.8. ([#313](https://github.com/heroku/buildpacks-python/pull/313))
@@ -276,7 +278,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Initial implementation. ([#3](https://github.com/heroku/buildpacks-python/pull/3))
 
-[unreleased]: https://github.com/heroku/buildpacks-python/compare/v0.21.0...HEAD
+[unreleased]: https://github.com/heroku/buildpacks-python/compare/v0.22.0...HEAD
+[0.22.0]: https://github.com/heroku/buildpacks-python/compare/v0.21.0...v0.22.0
 [0.21.0]: https://github.com/heroku/buildpacks-python/compare/v0.20.1...v0.21.0
 [0.20.1]: https://github.com/heroku/buildpacks-python/compare/v0.20.0...v0.20.1
 [0.20.0]: https://github.com/heroku/buildpacks-python/compare/v0.19.2...v0.20.0

buildpack.toml

@@ -2,7 +2,7 @@ api = "0.10"
 
 [buildpack]
 id = "heroku/python"
-version = "0.21.0"
+version = "0.22.0"
 name = "Heroku Python"
 homepage = "https://github.com/heroku/buildpacks-python"
 description = "Heroku's buildpack for Python applications."