chore(CHANGELOG): update to 5.31.0

Author: jarekdanielak

CHANGELOG.md

@@ -6,6 +6,11 @@ All notable changes to [bpmn-js-properties-panel](https://github.com/bpmn-io/bpm
 
 ___Note:__ Yet to be released changes appear here._
 
+## 5.31.0
+
+* `FEAT`: support ad-hoc subprocess ([#1105](https://github.com/bpmn-io/bpmn-js-properties-panel/pull/1105))
+* `DEPS`: update to `[email protected]`
+
 ## 5.30.1
 
 * `FIX`: ensure logical order of task listener event types ([#1102](https://github.com/bpmn-io/bpmn-js-properties-panel/pull/1102))