🔖 Prepare release of v3.1.0 (#1047)

## Description

This PR prepares the release of v3.1.0.

## Checklist:

- [x] The pull request only contains commits that are focused and
relevant to this change.
- [x] ~~I have added appropriate tests that cover the new/changed
functionality.~~
- [x] ~~I have updated the documentation to reflect these changes.~~
- [x] I have added entries to the changelog for any noteworthy
additions, changes, fixes, or removals.
- [x] I have added migration instructions to the upgrade guide (if
needed).
- [x] The changes follow the project's style guidelines and introduce no
new warnings.
- [x] The changes are fully tested and pass the CI checks.
- [x] I have reviewed my own code changes.

---------

Signed-off-by: Daniel Haag <[email protected]>
Co-authored-by: Lukas Burgholzer <[email protected]>

Author: denialhaag

CHANGELOG.md

@@ -9,6 +9,10 @@ This project adheres to [Semantic Versioning], with the exception that minor rel
 
 ## [Unreleased]
 
+## [3.1.0]
+
+_If you are upgrading: please see [`UPGRADING.md`](UPGRADING.md#310)._
+
 ### Added
 
 - ✨ Add MLIR pass for merging rotation gates ([#1019]) ([**@denialhaag**])
@@ -22,11 +26,12 @@ This project adheres to [Semantic Versioning], with the exception that minor rel
 
 - 🐛 Fix bug in MLIR roundtrip passes caused by accessing an invalidated iterator after erasure in a loop ([#932]) ([**@flowerthrower**])
 - 🐛 Add missing support for `sxdg` gates in Qiskit circuit import ([#930]) ([**@burgholzer**])
-- 🐛 Fix bug initialization of operations with duplicate operands ([#964]) ([**@ystade**])
+- 🐛 Fix bug related to initialization of operations with duplicate operands ([#964]) ([**@ystade**])
 - 🐛 Open issue for Qiskit upstream test only when the test is actually failing not when it was cancelled ([#973]) ([**@ystade**])
 
 ### Changed
 
+- ⬆️ Bump shared library ABI version from `3.0` to `3.1`.
 - ♻️ Switch from reference counting to mark-and-sweep garbage collection in decision diagram package ([#1020]) ([**@MatthiasReumann**], [**burgholzer**], [**q-inho**])
 - ♻️ Move the C++ code for the Python bindings to the top-level `bindings` directory ([#982]) ([**@denialhaag**])
 - ♻️ Move all Python code (no tests) to the top-level `python` directory ([#982]) ([**@denialhaag**])
@@ -111,7 +116,8 @@ _📚 Refer to the [GitHub Release Notes](https://github.com/munich-quantum-tool
 
 <!-- Version links -->
 
-[unreleased]: https://github.com/munich-quantum-toolkit/core/compare/v3.0.2...HEAD
+[unreleased]: https://github.com/munich-quantum-toolkit/core/compare/v3.1.0...HEAD
+[3.1.0]: https://github.com/munich-quantum-toolkit/core/compare/v3.0.2...v3.1.0
 [3.0.2]: https://github.com/munich-quantum-toolkit/core/compare/v3.0.1...v3.0.2
 [3.0.1]: https://github.com/munich-quantum-toolkit/core/compare/v3.0.0...v3.0.1
 [3.0.0]: https://github.com/munich-quantum-toolkit/core/compare/v2.7.0...v3.0.0

UPGRADING.md

@@ -4,6 +4,11 @@ This document describes breaking changes and how to upgrade. For a complete list
 
 ## [Unreleased]
 
+## [3.1.0]
+
+The shared library ABI version (`SOVERSION`) is increased from `3.0` to `3.1`.
+Thus, consuming libraries need to update their wheel repair configuration for cibuildwheel to ensure the mqt-core libraries are properly skipped in the wheel repair step.
+
 Even tough this is not a breaking change, it is worth mentioning to developers of MQT Core that all Python code (except tests) has been moved to the top-level `python` directory.
 Furthermore, the C++ code for the Python bindings has been moved to the top-level `bindings` directory.
 
@@ -63,9 +68,15 @@ Alternatively, CMake can be conveniently installed from PyPI using the [`cmake`]
 
 It also requires the `uv` library version 0.5.20 or higher.
 
+<!-- Version links -->
+
+[unreleased]: https://github.com/munich-quantum-toolkit/core/compare/v3.1.0...HEAD
+[3.1.0]: https://github.com/munich-quantum-toolkit/core/compare/v3.0.0...v3.1.0
+[3.0.0]: https://github.com/munich-quantum-toolkit/core/compare/v2.7.0...v3.0.0
+
+<!-- Other links -->
+
 [MQT DDSIM]: https://github.com/cda-tum/mqt-ddsim
 [MQT QMAP]: https://github.com/cda-tum/mqt-qmap
 [MQT QCEC]: https://github.com/cda-tum/mqt-qcec
 [MQT SyReC]: https://github.com/cda-tum/mqt-syrec
-[unreleased]: https://github.com/munich-quantum-toolkit/core/compare/v3.0.0...HEAD
-[3.0.0]: https://github.com/munich-quantum-toolkit/core/compare/v2.7.0...v3.0.0