CITest: migrate Trigger_athena_MC test

Migrate the trigger MC test from TestConfig[1] to CITest. Drop the usage
of the `runTrigCI.py` wrapper script.

Relates to ATLINFR-4360.

[1] https://gitlab.cern.ch/atlas-sit/CI/-/blob/master/TestConfig/Trigger_athena_MC.citest

AtlasTest/CITest/Athena.cmake

@@ -40,6 +40,14 @@ atlas_add_citest( Egamma
    SCRIPT ut_egammaARTJob_test.sh )
 
 
+#################################################################################
+# Trigger
+#################################################################################
+
+atlas_add_citest( TriggerMC
+   SCRIPT test_trigAna_RDOtoRDOTrig_v1Dev_build.py )
+
+
 # TODO: We stop here for now (migration ongoing...)
 return()
 
@@ -103,9 +111,6 @@ atlas_add_citest( Trigger_athenaHLT_decodeBS
 atlas_add_citest( Trigger_athenaHLT_data
    SCRIPT test_trigP1_v1PhysP1_build.py )
 
-atlas_add_citest( Trigger_athena_MC
-   SCRIPT test_trigAna_RDOtoRDOTrig_v1Dev_build.py )
-
 atlas_add_citest( Trigger_athena_data
    SCRIPT test_trig_data_v1Dev_build.py )