Updated changelog

Author: ArBridgeman

doc/changes/unreleased.md

@@ -1,5 +1,21 @@
 # Unreleased
 
+With this release, all projects using the PTB must use the `BaseConfig` introduced
+in [1.10.0](https://exasol.github.io/python-toolbox/main/changes/changes_1.10.0.html).
+
+As Python 3.9 reached its EOL on 2025-10-31, the PTB no longer supports Python 3.9,
+and it has added support for 3.14.
+
 ## Refactoring
 
-* #590: Dropped support for Python 3.9 and added support for Python 3.14
+* #590:
+   * Dropped support for Python 3.9 and added support for Python 3.14
+   * Enforced that the `PROJECT_CONFIG` defined in `noxconfig.py` must be derived from `BaseConfig`.
+     * Replaced `MINIMUM_PYTHON_VERSION` which acted as a back-up value for the nox session `artifacts:copy`
+     with `BaseConfig.minimum_python_version_`
+     * Replaced `_PYTHON_VERSIONS` which acted as a back-up value for the nox sessions `matrix:python` and `matrix:all`
+     with  `BaseConfig.python_versions_`
+     * Replaced `__EXASOL_VERSIONS` which acted as a back-up value for the nox sessions `matrix:exasol` and `matrix:all`
+     with `BaseConfig.python_versions_`
+     * Moved `pyupgrade_args` from being defined per PROJECT_CONFIG to a calculated property
+     `BaseConfig.pyupgrade_argument_`