Update MC21a_SingleBeamspot profile to match MC21_MultiBeamspot profile
During physics validation of variable beam spot simulation it was noted that it would be useful to separate the variable beam spot from the accompanying variation in mu-profile. With this change the MC21a_SingleBeamspot profile and the MC21_MultiBeamspot profile should now be identical except that the MC21a_SingleBeamspot profile is not split up by beam spot size.
NB Only the profiles for run number 410000 have been updated.
Changes in output of the DigitizationTests:test_Digi_tf_mc21a_ttbar.sh and DigitizationTests:test_Digi_tf_mc21a_presampling.sh ART jobs expected due to the altered mu-profile.