Drop test_MC16_ATLFASTII_ttbar_MP.sh ART test

This test is obsolete as we have AF3 now and the output of AFII is not reproducible in AthenaMP anyway.

This should "fix" ATLASSIM-5528 and ATLASSIM-5560.

Simulation/Tests/ISF_ValidationMT/test/test_MC16_ATLFASTII_ttbar_MP.sh

-#!/bin/sh
-#
-# art-description: MC16-style simulation using ATLFASTII
-# art-include: 21.0/Athena
-# art-include: 21.3/Athena
-# art-include: 21.9/Athena
-# art-include: master/Athena
-# art-type: grid
-# art-athena-mt: 8
-# art-output: test.HITS.pool.root
-
-# MC16 setup
-# ATLAS-R2-2016-01-00-01 and OFLCOND-MC16-SDR-14
-
-export ATHENA_CORE_NUMBER=8
-
-Sim_tf.py \
---multiprocess \
---conditionsTag 'default:OFLCOND-MC16-SDR-14' \
---physicsList 'FTFP_BERT_ATL' \
---truthStrategy 'MC15aPlus' \
---simulator 'ATLFASTII' \
---postInclude 'default:PyJobTransforms/UseFrontier.py' \
---preInclude 'EVNTtoHITS:SimulationJobOptions/preInclude.BeamPipeKill.py' \
---preExec 'EVNTtoHITS:simFlags.TightMuonStepping=True' \
---DataRunNumber '284500' \
---geometryVersion 'default:ATLAS-R2-2016-01-00-01' \
---inputEVNTFile "/cvmfs/atlas-nightlies.cern.ch/repo/data/data-art/SimCoreTests/valid1.410000.PowhegPythiaEvtGen_P2012_ttbar_hdamp172p5_nonallhad.evgen.EVNT.e4993.EVNT.08166201._000012.pool.root.1" \
---outputHITSFile "test.HITS.pool.root" \
---maxEvents 250 \
---imf False
-
-rc=$?
-echo  "art-result: $rc simulation"
-rc2=-9999
-if [ $rc -eq 0 ]
-then
-    ArtPackage=$1
-    ArtJobName=$2
-    art.py compare grid --entries 10 ${ArtPackage} ${ArtJobName} --mode=semi-detailed --order-trees --diff-root
-    rc2=$?
-fi
-echo  "art-result: $rc2 regression"