Investigate and enable RemoteAgentCompositeLoadingTest again

[laeubi]

As discussed below, the RemoteAgentCompositeLoadingTest is currently disabled (ad2b1b2184f7318bff03ba2da8f5c9da6731c97b) because it only fails on Jenkins. We should enable it again if we find a way to reproduce the failure locally...

I added a new PR without changes here ant it fails with the same tests

https://github.com/eclipse-tycho/tycho/pull/1547

but master succeeds:

https://ci.eclipse.org/tycho/job/tycho-github/job/master/

to make progress here I want to disable the test for now to see if anything else fails on Jenkins @akurtakov @mickaelistria any objections?

Originally posted by @laeubi in https://github.com/eclipse-tycho/tycho/issues/1543#issuecomment-1280403053