The wildfly-core-eap repo produces a org.jboss.as.domain-http-error-context with a jar as a dependency, and then code in the jboss-eap8 repo replaces its content with a different module.xml that uses a resource directory instead of a jar artifact. The leaves the jar artifact in the installation's eventual license.xml file along with this element:

<version>Not Installed</version>

The override of the module content should be moved from jboss-eap8 to wildfly-core-eap. As part of that, remove the org.wildfly.core:wildfly-domain-http-error-context dependency from the dependency list[1] used to produce the eap feature pack, and from the input file[2] used to produce the licenses.xml content.

[1] https://github.com/jbossas/wildfly-core-eap/blob/21.0.4.Final-redhat-dev/core-feature-pack/common/pom.xml#L680-L683
[2] https://github.com/jbossas/wildfly-core-eap/blob/21.0.4.Final-redhat-dev/core-feature-pack/common/src/main/resources/license/core-feature-pack-common-licenses.xml#L716-L731