scap seemingly allows <?PHP, but sync-dir doesn't?
scap only checks the files in the config directory for sanity and assumes that Jenkins checked other things so that's probably the difference there.
Part of me thinks scap should do it too... But it's extra time. In the grand scheme of how long scap takes now, it's probably not a great deal
But, I guess, fixing the wrong check in this case, is enough to fix this; as both <?PHP and <?php are valid, just our implemented checker was a bit naive (even if <?PHP isn't common)
Having scap lint every php file in the active branches is going to be slow and I honestly don't see the value in it. sync-file/sync-dir lint is more reasonable as they may be linting security patches or config files that haven't been through a linter in the CI tool chain.