Prepare release v0.2.1 (#250)

## heroku/go

- Added go1.21.9 (linux-aarch64), go1.21.9 (linux-x86_64), go1.22.2 (linux-aarch64), go1.22.2 (linux-x86_64).
### Changed

- Implement Buildpack API 0.10. ([#231](#231))

### Added

- Added linux aarch64 artifacts for >= go1.8.5. ([#230](#230))
- Added linux/arm64 buildpack target. ([#233](#233))

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

buildpacks/go/CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.2.1] - 2024-04-05
+
 - Added go1.21.9 (linux-aarch64), go1.21.9 (linux-x86_64), go1.22.2 (linux-aarch64), go1.22.2 (linux-x86_64).
 ### Changed
 
@@ -144,7 +146,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Initial implementation using libcnb.rs. ([#1](https://github.com/heroku/buildpacks-go/pull/1))
 
-[unreleased]: https://github.com/heroku/buildpacks-go/compare/v0.2.0...HEAD
+[unreleased]: https://github.com/heroku/buildpacks-go/compare/v0.2.1...HEAD
+[0.2.1]: https://github.com/heroku/buildpacks-go/compare/v0.2.0...v0.2.1
 [0.2.0]: https://github.com/heroku/buildpacks-go/compare/v0.1.16...v0.2.0
 [0.1.16]: https://github.com/heroku/buildpacks-go/compare/v0.1.15...v0.1.16
 [0.1.15]: https://github.com/heroku/buildpacks-go/compare/v0.1.14...v0.1.15

buildpacks/go/buildpack.toml

@@ -2,7 +2,7 @@ api = "0.10"
 
 [buildpack]
 id = "heroku/go"
-version = "0.2.0"
+version = "0.2.1"
 name = "Heroku Go"
 homepage = "https://github.com/heroku/buildpacks-go"
 description = "Heroku's buildpack for Go applications."