Backport the fix on computation of the radiation and nuclear interaction lengths to v6.24 #11080
Description
Would it be possible to backport:
#11060 (already merged into [root-project:master])
(from what I understand a followup PR is also needed).
to the v6.24 branch, and retag a new version of ROOT after that is done.
This would use use it as part of a LCG 101 patch release.
Many thanks.