Prepare release v0.3.0 (#262)

## heroku/go

### Added

- Support for `arm64` and multi-arch images. ([#261](#261))

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]
 
+## [0.3.0] - 2024-05-02
+
 ### Added
 
 - Support for `arm64` and multi-arch images. ([#261](https://github.com/heroku/buildpacks-go/pull/261))
@@ -150,7 +152,8 @@ 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/v0.2.1...HEAD
+[unreleased]: https://github.com/heroku/buildpacks-go/compare/v0.3.0...HEAD
+[0.3.0]: https://github.com/heroku/buildpacks-go/compare/v0.2.1...v0.3.0
 [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

buildpacks/go/buildpack.toml

@@ -2,7 +2,7 @@ api = "0.10"
 
 [buildpack]
 id = "heroku/go"
-version = "0.2.1"
+version = "0.3.0"
 name = "Heroku Go"
 homepage = "https://github.com/heroku/buildpacks-go"
 description = "Heroku's buildpack for Go applications."