Update change note

Author: atorralba

java/ql/lib/change-notes/2023-06-13-new-models.md

@@ -0,0 +1,8 @@
+---
+category: minorAnalysis
+---
+* Added models for the following packages:
+
+  * com.alibaba.fastjson2
+  * javax.management
+  * org.apache.http.client.utils