feat: add test data from RNTuple Viewer

[sathabbott]

Adding test data root files from rntviewer.

[eduardo-rodrigues]

Hello. Let me ping @ariostas as he has been dealing a lot with this package ...

A couple of things to have in mind:

• By default we want to know what these test files are for, so good to link to the issue that requires a new file for testing, etc. Do not hesitate to add some info more to the header of this PR.
• We try and follow a lightweight convention to know better what the files are about, see the many examples in the repo already.

[ariostas]

@sathabbott there's already quite a few RNTuples in here. Do you need anything in specific that is missing, or is it mainly since they are "standard" test files used somewhere else? If it's the latter, maybe it would be good to at least add a rntviewer- prefix to the file name, since RNTuple and multi are not very descriptive.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.38%. Comparing base (b6f7b74) to head (7fb1ce4).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #174   +/-   ##
=======================================
  Coverage   72.38%   72.38%           
=======================================
  Files           3        3           
  Lines         134      134           
=======================================
  Hits           97       97           
  Misses         37       37           

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[sathabbott]

@eduardo-rodrigues @ariostas
There isn't an issue that I can link to, I made this PR mainly because they are "standard" test files used somewhere else. I can remove the rc2 and rc3 files, and add a rntviewer- prefix.
I will update RNTuple and multi to be more descriptive.

[sathabbott]

Please let me know if the test file titles need another update.
Thank you for your time and attention on this!

[ariostas]

Thank you, @sathabbott! Looks good to me. If @eduardo-rodrigues has no further comments I can merge it and make a release.

[eduardo-rodrigues]

Hi. Sounds good, thanks to @ariostas's feedback. We're always happy to learn that this test data package is useful outside Scikit-HEP :).

[eduardo-rodrigues]

[@ariostas, do not forget to add @sathabbott to the list of contributors, https://github.com/scikit-hep/scikit-hep-testdata?tab=readme-ov-file#contributors. And it seems other people from recent PRs didn't make it to the list either ... and you didn't either, which is odd ;-)!]

[ariostas]

Oh that's a good point!

@all-contributors please add @sathabbott for data

[allcontributors]

@ariostas

I've put up a pull request to add @sathabbott! 🎉

[sathabbott]

Thank you both!