Prepare release v0.1.2 (#63)

## heroku/php

### Changed

- Updated buildpack display name and description. ([#57](https://github.com/heroku/buildpack-php/pull/57))

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

buildpacks/php/CHANGELOG.md

@@ -2,11 +2,13 @@
 
 All notable changes to this project will be documented in this file.
 
-The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+## [0.1.2] - 2023-10-24
+
 ### Changed
 
 - Updated buildpack display name and description. ([#57](https://github.com/heroku/buildpack-php/pull/57))
@@ -17,5 +19,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Initial implementation
 
-[unreleased]: https://github.com/heroku/buildpacks-php/compare/v0.1.1...HEAD
-[0.1.1]: https://github.com/heroku/buildpacks-php/releases/tag/v0.1.1
+[unreleased]: https://github.com/heroku/buildpacks-php/compare/v0.1.2...HEAD
+[0.1.2]: https://github.com/heroku/buildpacks-php/compare/v0.1.1...v0.1.2
+[0.1.1]: https://github.com/heroku/buildpacks-php/releases/tag/v0.1.1

buildpacks/php/buildpack.toml

@@ -2,7 +2,7 @@ api = "0.9"
 
 [buildpack]
 id = "heroku/php"
-version = "0.1.1"
+version = "0.1.2"
 name = "Heroku PHP"
 homepage = "https://github.com/heroku/buildpacks-php"
 description = "Heroku's buildpack for PHP applications."