Migrated TRT_ToT_dEdx to ReadDecorHandle for accessing pileup values from EventInfo
This is a followup on !31668 (merged), which introduced the access to
pileup information from EventInfo
via ReadDecorHandle
-s
Also cleaned up CMakeLists.txt
from atlas_depends_on_subdirs()
Tag: @phkoenig and @cgrefe who implemented recent changes to TRT_ToT_dEdx