JetRec: cmake fixes

Forgotten ${GTEST_INCLUDE_DIRS}. Can result in picking up an inconsistent version of the gtest headers, causing mysterious crashes.

This merge request affects 1 package:

• Reconstruction/Jet/JetRec

Adding @goetz as watcher

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

CI Result SUCCESS (hash 72b0cb2a)

	Athena	AthSimulation	AnalysisBase	AthGeneration
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
AnalysisBase: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 15999]

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

merged

mentioned in commit 84829b2f

added sweep:ignore label