Nuclear option to fix DL1 in derivations: disable SMT

This is the worst-case fix for ATLASDPD-1334. The latest failure we're seeing only happens in events with muons, so I've disabled SMT and DL1rmu.

No one will like this (@rateixei, @fdibello, @lidiaz, @cschiavi), but if we can't figure out a better solution we might need to go with this for now.

I'll be offline for the next few days, so I'll leave it to someone else to make the call.