🔖 Prepare release of v2.5.1 (#490)

Document the October 7 patch release, including the LLVM SDK defaults and
updated build dependencies. Add a brief note covering the LLVM version,
assertion selection, and removal of the Windows MLIR debug input.

Assisted-by: GPT-6 via Codex

Author: burgholzer

CHANGELOG.md

@@ -10,6 +10,25 @@ releases may include breaking changes.
 
 ## [Unreleased]
 
+## [2.5.1] - 2026-10-07
+
+_If you are upgrading: please see [`UPGRADING.md`](UPGRADING.md#251)._
+
+### Changed
+
+- ⬆️ Update [pypa/cibuildwheel] to `v4.3.0` ([#489])
+- ⬆️ Default LLVM workflows to LLVM 23.1.2 using
+  [munich-quantum-software/setup-mlir] `v1.5.0` ([#486]) ([**@burgholzer**])
+- ⚡ Use assertion-free LLVM SDKs by default for macOS and Windows wheel builds,
+  with the `mlir-assertions` input to retain assertions. Development workflows
+  retain assertions ([#486]) ([**@burgholzer**])
+- ⬆️ Update [astral-sh/setup-uv] to `v10.2.0` ([#484])
+
+### Removed
+
+- 🔥 Remove the obsolete `mlir-debug` input from Windows C++ tests ([#486])
+  ([**@burgholzer**])
+
 ## [2.5.0] - 2026-09-25
 
 _If you are upgrading: please see [`UPGRADING.md`](UPGRADING.md#250)._
@@ -546,7 +565,8 @@ _📚 Refer to the [GitHub Release Notes] for previous changelogs._
 
 <!-- Version links -->
 
-[unreleased]: https://github.com/munich-quantum-toolkit/workflows/compare/v2.5.0...HEAD
+[unreleased]: https://github.com/munich-quantum-toolkit/workflows/compare/v2.5.1...HEAD
+[2.5.1]: https://github.com/munich-quantum-toolkit/workflows/releases/tag/v2.5.1
 [2.5.0]: https://github.com/munich-quantum-toolkit/workflows/releases/tag/v2.5.0
 [2.4.2]: https://github.com/munich-quantum-toolkit/workflows/releases/tag/v2.4.2
 [2.4.1]: https://github.com/munich-quantum-toolkit/workflows/releases/tag/v2.4.1
@@ -596,6 +616,9 @@ _📚 Refer to the [GitHub Release Notes] for previous changelogs._
 
 <!-- PR links -->
 
+[#489]: https://github.com/munich-quantum-toolkit/workflows/pull/489
+[#486]: https://github.com/munich-quantum-toolkit/workflows/pull/486
+[#484]: https://github.com/munich-quantum-toolkit/workflows/pull/484
 [#476]: https://github.com/munich-quantum-toolkit/workflows/pull/476
 [#474]: https://github.com/munich-quantum-toolkit/workflows/pull/474
 [#472]: https://github.com/munich-quantum-toolkit/workflows/pull/472
@@ -688,4 +711,5 @@ _📚 Refer to the [GitHub Release Notes] for previous changelogs._
 [GitHub Release Notes]: https://github.com/munich-quantum-toolkit/workflows/releases
 [munich-quantum-software/setup-mlir]: https://github.com/munich-quantum-software/setup-mlir
 [pypa/cibuildwheel]: https://github.com/pypa/cibuildwheel
+[astral-sh/setup-uv]: https://github.com/astral-sh/setup-uv
 [CMake presets]: https://cmake.org/cmake/help/latest/manual/cmake-presets.7.html

UPGRADING.md

@@ -6,6 +6,14 @@ of changes, including minor and patch releases, please refer to the
 
 ## [Unreleased]
 
+## [2.5.1]
+
+MLIR-enabled workflows default to LLVM 23.1.2; set `llvm-version` explicitly to
+retain an older version. macOS and Windows wheel builds default to
+assertion-free SDKs; use `mlir-assertions: true` for older SDKs or builds
+needing assertions. Linux wheel projects select their SDK inside cibuildwheel.
+Remove the `mlir-debug` input from Windows C++ test jobs.
+
 ## [2.5.0]
 
 ### Automatic Python stub updates
@@ -792,7 +800,8 @@ invocations under Windows.
 
 <!-- Version links -->
 
-[unreleased]: https://github.com/munich-quantum-toolkit/workflows/compare/v2.5.0...HEAD
+[unreleased]: https://github.com/munich-quantum-toolkit/workflows/compare/v2.5.1...HEAD
+[2.5.1]: https://github.com/munich-quantum-toolkit/workflows/compare/v2.5.0...v2.5.1
 [2.5.0]: https://github.com/munich-quantum-toolkit/workflows/compare/v2.4.2...v2.5.0
 [2.4.0]: https://github.com/munich-quantum-toolkit/workflows/compare/v2.3.0...v2.4.0
 [2.3.0]: https://github.com/munich-quantum-toolkit/workflows/compare/v2.2.3...v2.3.0