Prepare release v6.0.0 (#520)

## heroku/python

### Changed

- Updated pip from 25.3 to 26.0.1. ([#508](#508))
- Updated uv from 0.10.1 to 0.10.7. ([#518](#518))
- Explicitly configured uv to use hard links to maintain the behaviour of previous versions. ([#519](#519))

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]
 
+## [6.0.0] - 2026-03-03
+
 ### Changed
 
 - Updated pip from 25.3 to 26.0.1. ([#508](https://github.com/heroku/buildpacks-python/pull/508))
@@ -590,7 +592,8 @@ 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/v5.1.0...HEAD
+[unreleased]: https://github.com/heroku/buildpacks-python/compare/v6.0.0...HEAD
+[6.0.0]: https://github.com/heroku/buildpacks-python/compare/v5.1.0...v6.0.0
 [5.1.0]: https://github.com/heroku/buildpacks-python/compare/v5.0.0...v5.1.0
 [5.0.0]: https://github.com/heroku/buildpacks-python/compare/v4.1.2...v5.0.0
 [4.1.2]: https://github.com/heroku/buildpacks-python/compare/v4.1.1...v4.1.2

buildpack.toml

@@ -2,7 +2,7 @@ api = "0.10"
 
 [buildpack]
 id = "heroku/python"
-version = "5.1.0"
+version = "6.0.0"
 name = "Heroku Python"
 homepage = "https://github.com/heroku/buildpacks-python"
 description = "Heroku's buildpack for Python applications."