chore(docs): add spring 6 info to migration guide

camunda/camunda-bpm-platform#4869

Author: joaquinfelici

content/update/minor/722-to-723/_index.md

@@ -58,4 +58,8 @@ You can read more about the warnings [here](https://www.graalvm.org/jdk17/refere
 If you want to ensure the best performance for JS execution, you can always configure the GraalVM Compiler with your JDK of choice, or use the GraalVM JDK.
 
 More information on how to do this can be found in the official [GraalVM documentation](https://www.graalvm.org/jdk17/reference-manual/js/RunOnJDK/#graalvm-javascript-on-jdk-11).
-{{< /note >}}
+{{< /note >}}
+
+# Spring Framework Upgrade
+
+Starting with version `7.23`, the `camunda-engine` artifact now uses Spring Framework 6 by default, replacing Spring 5 from previous releases.