The Deployment (which also holds the Archive) for each test class is added to DeploymentContextImpl.stores. A Deployment is deactivated properly but it is not getting removed until the Manager shuts down.

This can easily blow the heap of the executing JVM in case you have many test classes and/or large archives to deploy.
In our environment the JVM forked by maven surefire dies with an OOM after just ~20 test classes. Xmx is set to 512m.

PS: Another user came across this problem too: https://developer.jboss.org/thread/250124