Prepare release v2.3.0 (#396)

## heroku/python

### Changed

- Updated uv from 0.7.20 to 0.8.4. ([#393](#393))

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]
 
+## [2.3.0] - 2025-08-01
+
 ### Changed
 
 - Updated uv from 0.7.20 to 0.8.4. ([#393](https://github.com/heroku/buildpacks-python/pull/393))
@@ -393,7 +395,8 @@ 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/v2.2.3...HEAD
+[unreleased]: https://github.com/heroku/buildpacks-python/compare/v2.3.0...HEAD
+[2.3.0]: https://github.com/heroku/buildpacks-python/compare/v2.2.3...v2.3.0
 [2.2.3]: https://github.com/heroku/buildpacks-python/compare/v2.2.2...v2.2.3
 [2.2.2]: https://github.com/heroku/buildpacks-python/compare/v2.2.1...v2.2.2
 [2.2.1]: https://github.com/heroku/buildpacks-python/compare/v2.2.0...v2.2.1

buildpack.toml

@@ -2,7 +2,7 @@ api = "0.10"
 
 [buildpack]
 id = "heroku/python"
-version = "2.2.3"
+version = "2.3.0"
 name = "Heroku Python"
 homepage = "https://github.com/heroku/buildpacks-python"
 description = "Heroku's buildpack for Python applications."