RootUtils: fix build with LCG_106a
Cherry-pick the following changes from main to 24.0: !69750 (merged): RootUtils: Update reference to libcppyy for root master. !70519 (merged): Avoid deprecated attribute syntax for TFile
Relates to ATLINFR-5582
Cherry-pick the following changes from main to 24.0: !69750 (merged): RootUtils: Update reference to libcppyy for root master. !70519 (merged): Avoid deprecated attribute syntax for TFile
Relates to ATLINFR-5582