Updated MuonPhysVal CA config to avoid trigger decision tool if not used (fix ATLSWUPGR-189)
The Muon PhysVal config configures the retrieval of the TriggerDecisionTool, which is not used since the DoTrigMuonValidation flag is left to its default False value. This MR avoids the retrieval of this tool in the baseline config used in physics validation, while introducing some trigger config in case there is some use case beyond what's currently used in Athena. Fixes the crash encountered in Upgrade PhysVal, where no trigger content is present for now.