Revert "[DF] Work around TTree::GetLeaf bug in GetBranchOrLeafTypeName"
Revert "[DF] Work around TTree::GetLeaf bug in GetBranchOrLeafTypeName"

The workaround should now be needed anymore, as ROOT-10942 has now been
properly fixed in TTree.
This reverts commit 8b95a161a57332542be26a091245e445ac769bc4.

olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,olifre/root,olifre/root,root-mirror/root,olifre/root,olifre/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root