Prepare release v0.9.0 (#201)

## heroku/python

### Changed

- Updated setuptools from 68.0.0 to 69.5.1. ([#200](#200))
- Updated wheel from 0.42.0 to 0.43.0. ([#179](#179))
- The buildpack now implements Buildpack API 0.10 instead of 0.9, and so requires `lifecycle` 0.17.x or newer. ([#197](#197))
- The buildpack's base image compatibility metadata is now declared using `[[targets]]` instead of `[[stacks]]`. ([#197](#197))
- Changed compression format and S3 URL for Python runtime archives. ([#197](#197))

### Removed

- Removed support for Python 3.7. ([#197](#197))

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

Author: heroku-linguist[bot]

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.9.0] - 2024-05-03
+
 ### Changed
 
 - Updated setuptools from 68.0.0 to 69.5.1. ([#200](https://github.com/heroku/buildpacks-python/pull/200))
@@ -129,7 +131,8 @@ 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/v0.8.4...HEAD
+[unreleased]: https://github.com/heroku/buildpacks-python/compare/v0.9.0...HEAD
+[0.9.0]: https://github.com/heroku/buildpacks-python/compare/v0.8.4...v0.9.0
 [0.8.4]: https://github.com/heroku/buildpacks-python/compare/v0.8.3...v0.8.4
 [0.8.3]: https://github.com/heroku/buildpacks-python/compare/v0.8.2...v0.8.3
 [0.8.2]: https://github.com/heroku/buildpacks-python/compare/v0.8.1...v0.8.2

buildpack.toml

@@ -2,7 +2,7 @@ api = "0.10"
 
 [buildpack]
 id = "heroku/python"
-version = "0.8.4"
+version = "0.9.0"
 name = "Heroku Python"
 homepage = "https://github.com/heroku/buildpacks-python"
 description = "Heroku's buildpack for Python applications."