Prepare release 0.9.1

This is a breaking change, 0.9.0 should be yanked. See
#568

Author: sosthene-nitrokey

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
-## [Unreleased]
+## [v0.9.1] - 2025-08-19
 
 ### Added
 
@@ -698,7 +698,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Initial release
 
-[Unreleased]: https://github.com/rust-embedded/heapless/compare/v0.9.0...HEAD
+[Unreleased]: https://github.com/rust-embedded/heapless/compare/v0.9.1...HEAD
+[v0.9.0]: https://github.com/rust-embedded/heapless/compare/v0.9.0...v0.9.1
 [v0.9.0]: https://github.com/rust-embedded/heapless/compare/v0.8.0...v0.9.0
 [v0.8.0]: https://github.com/rust-embedded/heapless/compare/v0.7.16...v0.8.0
 [v0.7.16]: https://github.com/rust-embedded/heapless/compare/v0.7.15...v0.7.16

Cargo.toml

@@ -12,7 +12,7 @@ keywords = ["static", "no-heap"]
 license = "MIT OR Apache-2.0"
 name = "heapless"
 repository = "https://github.com/rust-embedded/heapless"
-version = "0.9.0"
+version = "0.9.1"
 
 [features]
 bytes = ["dep:bytes"]