Update getEntryRecord

In this MR:

• Update the getEntryRecord function fot HepMC3 compatibility
• Use free functions from HepMC:: namespace

changed title from Updated getEntryRecord to WIP Updated getEntryRecord

This merge request affects 1 package:

• MuonSpectrometer/MuonReconstruction/MuonRecTools/MuonTruthTools

This merge request affects 2 files:

• MuonSpectrometer/MuonReconstruction/MuonRecTools/MuonTruthTools/src/MuonTruthTrackBuilder.cxx
• MuonSpectrometer/MuonReconstruction/MuonRecTools/MuonTruthTools/src/MuonTruthTrackBuilder.h

Adding @goetz ,@rosati ,@wleight ,@nkoehler as watchers

added MuonSpectrometer master review-pending-level-1 labels

jenkins please retry a build

CI Result SUCCESS (hash 48e0a99c)

	Athena	AthSimulation	AthGeneration	AnalysisBase
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 24675]

changed title from WIP Updated getEntryRecord to Update getEntryRecord

changed the description

added review-approved label and removed review-pending-level-1 label

mentioned in commit 648aabec

merged

added sweep:ignore label