Eliminate stale BIRT contributions

[merks]

@zulus @kgibm @ajohnson1 @krumts

Currently MAT and PDT contribute stale BIRT content to SimRel:

Here are the dependencies:

Looking at where those come from, I see they are contributed via MAT's contributed repository:

MAT's continued participation is in doubt though. I've opened the following issue to express those doubts:

eclipse-mat/mat#172

If MAT is disabled then PDT will fail to aggregate.

| Missing requirement: PDT Profiler UI Plug-in 8.4.0.202512011310 (org.eclipse.php.profile.ui 8.4.0.202512011310) requires 'osgi.bundle; org.eclipse.birt.chart.engine 0.0.0' but it could not be found

I can't really disable PDT's profiler feature because it's used in the PHP product.

[ewillink]

(MoDisco was also a user, but MoDisco is on the way out so no problem there any more.)