[ATR-30804] Add ShallowCopy output property to HLTEDMCreator for scheduler awareness
Eureka... I remained suspicious that GapFiller specifically couldn't declare output dependencies on the (jet) shallow copy containers despite this working for everything else including their decorations. Examining the declaration of the shallow copy WriteHandleArray, the lack of property decorations unlike in the ReadHandleArray declarations seemed wrong, and I recalled that the scheduler needs the properties in order to determine the data dependencies. Upon adding the property declaration, GapFiller starts doing its job correctly, and SGInputLoader is no longer invoked for HLT_AntiKt4EMPFlowJets_jes_ftf.