Update changelog for v0.15 release (#485)

* [pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/pre-commit/mirrors-prettier: v3.0.3 → v4.0.0-alpha.8](pre-commit/mirrors-prettier@v3.0.3...v4.0.0-alpha.8)
- [github.com/astral-sh/ruff-pre-commit: v0.1.9 → v0.1.14](astral-sh/ruff-pre-commit@v0.1.9...v0.1.14)

* Fix vstack for scipy 1.12

* Update Changelog for v0.15.0

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -8,7 +8,7 @@ and this project adheres to [Semantic Versioning][].
 [keep a changelog]: https://keepachangelog.com/en/1.0.0/
 [semantic versioning]: https://semver.org/spec/v2.0.0.html
 
-## Unreleased
+## v0.15.0
 
 ### Fixes