SimCoreTestsMT: Drop diff-pool checks for MT jobs
diff-pool checks can show differences due to the different ordering of events in the output file.
This is nothing to be concerned out, so disabling them for test_AtlasG4_FastCaloSim_MT.sh
and
test_AtlasG4_FastCaloSim_MTvsST.sh
. Should fix ATLASSIM-7107, ATLASSIM-7109 and ATLASSIM-7110.