Release v0.3.1 (#218)

* Add [0.3.1] section in changelog
* Update version to 0.3.1

Author: ValerianRey

CHANGELOG.md

@@ -8,6 +8,8 @@ changes that do not affect the user.
 
 ## [Unreleased]
 
+## [0.3.1] - 2024-12-21
+
 ### Changed
 
 - Improved the performance of the graph traversal function called by `backward` and `mtl_backward`

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "pdm.backend"
 
 [project]
 name = "torchjd"
-version = "0.3.0"
+version = "0.3.1"
 description = "Library for Jacobian Descent with PyTorch."
 readme = "README.md"
 authors = [