Fix path errors while analyzing packages referencing ${java.home}

[ftake]

Some packages (e.g., Javassist) refere ${java.home} in of their dependencies. This commit add "java.home" to the passthrough properties list and prevent maven from complaining such paths are not absolute.

Caused by: org.apache.maven.model.building.ModelBuildingException: 1 problem was encountered while building the effective model for org.javassist:javassist:3.29.2-GA
[ERROR] 'dependencies.dependency.systemPath' for com.sun:tools:jar must specify an absolute path but is ${java.home}/lib/jrt-fs.jar @ 

	at org.apache.maven.model.building.DefaultModelProblemCollector.newModelBuildingException(DefaultModelProblemCollector.java:176)
	at org.apache.maven.model.building.DefaultModelBuilder.build(DefaultModelBuilder.java:508)
	at org.apache.maven.model.building.DefaultModelBuilder.build(DefaultModelBuilder.java:410)
	at org.apache.maven.model.building.DefaultModelBuilder.build(DefaultModelBuilder.java:243)
	at org.spdx.sbom.gradle.maven.PomResolver.resolveEffectivePom(PomResolver.java:207)
	... 93 more

[loosebazooka]

Thanks for the contribution