[FSSDK-12094] chore: preparing for release v5.4.0 (#473)

* [FSSDK-12094] chore: preparing for release v5.3.1

* Update changelog

* Updated 5.3.0 version with holdout

* Correct the version number

* Correct the changelog with holdout features

Author: esrakartalOpt

CHANGELOG.md

@@ -1,5 +1,24 @@
 # Optimizely Python SDK Changelog
 
+## 5.4.0
+December 19th, 2025
+
+### New Features
+
+Holdout features:
+
+- Added support for Holdouts in Feature Experimentation, enabling global traffic exclusion from experiments for statistical confidence validation. ([#469](https://github.com/optimizely/python-sdk/pull/469))
+- Added holdout support for default decision service ([#467](https://github.com/optimizely/python-sdk/pull/467))
+- Project Config updated for Holdout ([#464](https://github.com/optimizely/python-sdk/pull/464))
+
+---
+
+### Bug Fixes
+- Resolved issues with Holdout impression event handling and notification delivery. ([#471](https://github.com/optimizely/python-sdk/pull/471))
+
+---
+
+
 ## 5.3.0
 November 13th, 2025
 

optimizely/version.py

@@ -11,5 +11,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-version_info = (5, 3, 0)
+version_info = (5, 4, 0)
 __version__ = '.'.join(str(v) for v in version_info)