Update changelog for Groovy.

Author: nedtwigg

CHANGES.md

@@ -14,6 +14,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * We are now opting in to Gradle's new stable configuration cache. ([#1591](https://github.com/diffplug/spotless/pull/1591))
 * Adopt [Equo Solstice OSGi and p2 shim](https://github.com/equodev/equo-ide/tree/main/solstice) to update all Eclipse-based plugins. ([#1524](https://github.com/diffplug/spotless/pull/1524))
   * Eclipse JDT now supports `4.9` through `4.26`. Also we now recommend dropping the last `.0`, e.g. `4.26` instead of `4.26.0`, you'll get warnings to help you switch.
+  * Eclipse Groovy now supports `4.18` through `4.26`. Also we now recommend dropping the last `.0`, e.g. `4.26` instead of `4.26.0`, you'll get warnings to help you switch.
 
 ## [2.36.0] - 2023-02-27
 ### Added