ReadoutGeometryBase - Ensure that the ATLAS eigen headers are called before external headers

Intermediate fix to ATLINFR-4280

This merge request affects 1 package:

• DetectorDescription/ReadoutGeometryBase

This merge request affects 2 files:

• DetectorDescription/ReadoutGeometryBase/ReadoutGeometryBase/DetectorDesign.h
• DetectorDescription/ReadoutGeometryBase/ReadoutGeometryBase/SolidStateDetectorElementBase.h

Adding @stavrop ,@rbianchi ,@jojungge as watchers

added Geometry HGTD ITk master review-pending-level-1 labels

changed the description

CI Result SUCCESS (hash 8df58d66)

	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 40239]

Approving -- L1

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

merged

mentioned in commit 6dec0e56

added sweep:ignore label