Prepare for release

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.4.0] - Unreleased
+## [0.4.0] - 2023-07-06
 ### Added
 - Functions to concatenate input damages across batches. ([PR #83](https://github.com/ClimateImpactLab/dscim/pull/83), [@davidrzhdu](https://github.com/davidrzhdu))
 - New unit tests for [dscim/utils/input_damages.py](https://github.com/ClimateImpactLab/dscim/blob/main/src/dscim/preprocessing/input_damages.py). ([PR #68](https://github.com/ClimateImpactLab/dscim/pull/68), [@davidrzhdu](https://github.com/davidrzhdu))