DataModelRoot: Update for thread-safety checker const changes.

The thread-safety checker is getting more strict on const checks. Fix resulting warnings.

This merge request affects 1 package:

• Control/DataModelRoot

This merge request affects 2 files:

• Control/DataModelRoot/DataModelRoot/RootType.h
• Control/DataModelRoot/src/RootType.cxx

Adding @ssnyder as watcher

added Core master review-pending-level-1 labels

CI Result FAILURE (hash 23bcfdac)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis	DetCommon
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
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 42415]

CI failures are unrelated. Approved

Sergei L1

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

merged

mentioned in commit 696ada70

added sweep:ignore label