Remove PFO Validation Code

This MR removes validation code for the deprecated PFO. ART tests are updated to validate FlowElements instead of PFO.

This merge request affects 5 packages:

• PhysicsAnalysis/PhysicsValidation/PhysValMonitoring
• Reconstruction/PFlow/PFlowValidation/PFODQA
• Reconstruction/PFlow/PFlowValidation/PFOHistUtils
• Reconstruction/RecExample/RecJobTransformTests
• Tools/Tier0ChainTests

Affected files list will not be printed in this case

Adding @goetz ,@mhodgkin as watchers

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

CI Result SUCCESS (hash 6292f2e3)

	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 37689]

Changes look fine and CI is good. Approving. Clara (L1)

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

merged

mentioned in commit 2e61b34e

added sweep:ignore label