RuleTaskHandler doesn't work in spring boot immutable container

There is an edge case where BAPL-1531 abd https://github.com/kiegroup/jbpm/blob/7.48.x/jbpm-workitems/jbpm-workitems-bpmn2/src/main/java/org/jbpm/process/workitem/bpmn2/AbstractRuleTaskHandler.java#L69 doesn't work together.

If we deploy 2 KJARs onto spring boot (with config from BAPL-1531 in place).

First KJAR includes BPMN process

Second KJAR includes DMN Model

KJAR 1 is configured with https://github.com/kiegroup/jbpm/blob/master/jbpm-workitems/jbpm-workitems-bpmn2/src/main/java/org/jbpm/process/workitem/bpmn2/DecisionTaskHandler.java which points to KJAR2 for the purposes of bpmn-dmn invocation.

This particular use case fails because KJAR2 is being loaded from the maven repository, see:

https://github.com/kiegroup/jbpm/blob/7.48.x/jbpm-workitems/jbpm-workitems-bpmn2/src/main/java/org/jbpm/process/workitem/bpmn2/AbstractRuleTaskHandler.java#L111

But in case of spring boot immutable container, there is no maven repo available - all the KJARs part of the spring boot fat jar.

One of the possible solution is to allow RuleTaskHandler to lookup KJARs from the classpath (as opposed to maven repo).

Reproducer repo:

https://gitlab.consulting.redhat.com/agiertli/rule-task-spring-boot-reproducer

Idea for a solution:

https://gitlab.consulting.redhat.com/agiertli/rule-task-spring-boot-reproducer/-/tree/solution