Prepare release v0.4.3 (#291)

## heroku/go

- Added go1.23.0 (linux-amd64), go1.23.0 (linux-arm64).

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

buildpacks/go/CHANGELOG.md

@@ -7,7 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.4.3] - 2024-08-13
+
 - Added go1.23.0 (linux-amd64), go1.23.0 (linux-arm64).
+
 ## [0.4.2] - 2024-08-07
 
 - Added go1.21.13 (linux-arm64), go1.21.13 (linux-amd64), go1.22.6 (linux-amd64), go1.22.6 (linux-arm64).
@@ -178,7 +181,8 @@ 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/v0.4.2...HEAD
+[unreleased]: https://github.com/heroku/buildpacks-go/compare/v0.4.3...HEAD
+[0.4.3]: https://github.com/heroku/buildpacks-go/compare/v0.4.2...v0.4.3
 [0.4.2]: https://github.com/heroku/buildpacks-go/compare/v0.4.1...v0.4.2
 [0.4.1]: https://github.com/heroku/buildpacks-go/compare/v0.4.0...v0.4.1
 [0.4.0]: https://github.com/heroku/buildpacks-go/compare/v0.3.1...v0.4.0

buildpacks/go/buildpack.toml

@@ -2,7 +2,7 @@ api = "0.10"
 
 [buildpack]
 id = "heroku/go"
-version = "0.4.2"
+version = "0.4.3"
 name = "Heroku Go"
 homepage = "https://github.com/heroku/buildpacks-go"
 description = "Heroku's buildpack for Go applications."