CaloEvent: Add missing const qualifiers.

Fixes warnings about ambiguous comparisons in xAODCaloEventCnv when compiling with clang / c++20.

This merge request affects 1 package:

• Calorimeter/CaloEvent

This merge request affects 2 files:

• Calorimeter/CaloEvent/CaloEvent/CaloCluster.h
• Calorimeter/CaloEvent/src/CaloCluster.cxx

Adding @pavol as watcher

added Calorimeter JetEtmiss master review-pending-level-1 labels

CI Result FAILURE (hash 5aa5ac29)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis	DetCommon
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
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
AthAnalysis: number of compilation errors 0, warnings 0
DetCommon: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 44874]

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

merged

mentioned in commit 74a4eb05

added sweep:ignore label