Make PhysValMET compatible with updated JVT tool
The JVT tool was changed in !31218 (merged) to access jet decorations using DecorHandles. This means each instance of the JVT tool can now only be used with one jet collection. PhysValMET had been using a single JVT tool for multiple jet collections; this fixes that issue.
I also cleaned up some obsolete code while I was at it, including everything related to validation for the AntiKt4LCTopo jet collection (which is deprecated).
Fixes ATLASRECTS-5387.