Update changelog.

Author: nedtwigg

CHANGES.md

@@ -10,6 +10,8 @@ This document is intended for Spotless developers.
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Changes
+* Bump the dev version of Gradle from `7.5.1` to `7.6` ([#1409](https://github.com/diffplug/spotless/pull/1409))
 
 ## [2.31.1] - 2023-01-02
 ### Fixed