Draft: EventLoop Boost Fix, main branch (2023.07.14.)

gt_SubmitDirManager.cxx uses <boost/filesystem.hpp>, so we need to use that Boost component explicitly.

I came across this issue while building AnalysisBase on x86_64-el9-gcc11-opt, while testing a fix (atlasexternals!1032 (merged)) for !64280 (merged). I was so ready to blame @averbyts's !64255 (merged) update when I saw the failure because of boost::filesystem, but of course that had nothing to do with it. The reason I bring it up is that while I wanted to open this MR, it may be the best idea to just wait for !64255 (merged) to be swept into main, as that will actually be a nicer fix for this issue. Still wanted to open this to keep track of things...

There were much more cases like that. I've fixed some, but not all.

At least this was the only thing preventing me from building AnalysisBase on RHEL9...

I believe this is all sorted out by now thanks to !64255 (merged) and !64388 (merged).

closed