Prepare release v0.1.9 (#167)

## heroku/dotnet

### Added

- Support for .NET SDK versions: 9.0.101 (linux-amd64), 9.0.101 (linux-arm64).

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

buildpacks/dotnet/CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.1.9] - 2024-12-04
+
 ### Added
 
 - Support for .NET SDK versions: 9.0.101 (linux-amd64), 9.0.101 (linux-arm64).
@@ -70,7 +72,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Initial implementation.
 
-[unreleased]: https://github.com/heroku/buildpacks-dotnet/compare/v0.1.8...HEAD
+[unreleased]: https://github.com/heroku/buildpacks-dotnet/compare/v0.1.9...HEAD
+[0.1.9]: https://github.com/heroku/buildpacks-dotnet/compare/v0.1.8...v0.1.9
 [0.1.8]: https://github.com/heroku/buildpacks-dotnet/compare/v0.1.7...v0.1.8
 [0.1.7]: https://github.com/heroku/buildpacks-dotnet/compare/v0.1.6...v0.1.7
 [0.1.6]: https://github.com/heroku/buildpacks-dotnet/compare/v0.1.5...v0.1.6

buildpacks/dotnet/buildpack.toml

@@ -2,7 +2,7 @@ api = "0.10"
 
 [buildpack]
 id = "heroku/dotnet"
-version = "0.1.8"
+version = "0.1.9"
 name = "Heroku .NET"
 homepage = "https://github.com/heroku/buildpacks-dotnet"
 description = "Heroku's buildpack for .NET applications."