Add initial R-universe Github action

[sarahkelley42]

Testing changes to the yml, not ready for merge yet.

[sarahkelley42]

@kuwisdelu I could use your input on this; I believe this is the recommended setup per the bioconductor docs, with a variation I threw in from the r-universe-org readme because I'm not totally sure what the org fields actually do in these jobs. I'm not sure yet whether this actually catches test failures or if it's strictly a build.

Do you happen to have an example code change that might break things that I can cherry-pick and test with? Hoping to sanity check before calling this merge-ready.

[sarahkelley42]

Although, early positive signal, we do get some failure:

  ✖ ERROR: At least 80% of man pages documenting exported objects must have
  runnable examples.
    The following pages do not:
      • Cardinal-package.Rd
      • ...
      • writeMSIData.Rd

https://github.com/Cardinalverse/Cardinal/actions/runs/34848819264/job/103994206520?pr=79