RNTupleART: Start running in dev4LCG and require exact branch matching in comparisons

1. Now that dev4LCG nightly has a more recent ROOT version, let's start running RNTuple tests there as well.
2. After sorting out ATEAM-974, all tests are fully functional, including the ones that do a full DAOD comparison w/ 1000 events:

Here, adopting the --exact-branches in diff-root so that warnings for branches missing in either file will be treated as an error (note: there is no such mismatch, so this won't affect the results).

We can start using these two tests as a validation step when testing local RNTuple changes:

• test_data23_daod_phys_physlite_diff.sh
• test_mc23_daod_phys_physlite_diff.sh

cc: @gemmeren @mnowak