Prepare release v0.5.6 (#712)

<!--
SPDX-FileCopyrightText: ASSUME Developers

SPDX-License-Identifier: AGPL-3.0-or-later
-->


## Description
New Release as per the release notes. 

## Checklist
- [x] Documentation updated (docstrings, READMEs, user guides, inline
comments, `doc` folder updates etc.)
- [x] New unit/integration tests added (if applicable)
- [x] Changes noted in release notes (if any)
- [x] Consent to release this PR's code under the GNU Affero General
Public License v3.0

Author: kim-mskw

CONTRIBUTING.md

@@ -68,17 +68,8 @@ pip install -e ".[testing]"
 
 ### Creating a new release
 
-To release a new version, increase the version in `pyproject.toml` and create a git tag of the release commit and release notes in GitHub.
-To push to PyPi run:
-
-```
-rm -r dist
-python -m build .
-twine upload --repository pypi dist/*
-```
-
-See also: https://twine.readthedocs.io/en/stable/index.html#using-twine
-
+To release a new version, create a git tag of the release commit and release notes in GitHub (also possible via `Draft new release` function of Github). No adjusted toml file necessary anymore.
+A github action automatically uploads the release to PyPI.
 The upload to PyPi has to be confirmed by one of the core developers.
 
 ## Building documentation

docs/source/release_notes.rst

@@ -12,6 +12,9 @@ Upcoming Release
   The features in this section are not released yet, but will be part of the next release! To use the features already you have to install the main branch,
   e.g. ``pip install git+https://github.com/assume-framework/assume``
 
+0.5.6 - (23th December 2025)
+============================
+
 **Bug Fixes:**
 
 - **Changed action clamping**: The action clamping was changed to extreme values defined by dicts. Instead of using the min and max of a forward pass in the NN, the clamping is now based on the activation function of the actor network. Previously, the output range was incorrectly assumed based only on the input, which failed when weights were negative due to Xavier initialization.