Install package build deps on MacOS

[andrjohns]

Submission Checklist

• Run unit tests
• Declare copyright holder and agree to license (see below)

Summary

The MacOS R-Devel CI has been failing since R no longer bundles libintl, and the current setup-r-dependencies action doesn't install system dependencies on macos, so it was recommended we use separate action for this

Copyright and Licensing

Please list the copyright holder for the work you are submitting
(this will be you or your assignee, such as a university or company):
Andrew Johnson

By submitting this pull request, the copyright holder is agreeing to
license the submitted work under the following licenses:

• Code: BSD 3-clause (https://opensource.org/licenses/BSD-3-Clause)
• Documentation: CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

[tdhock]

I was having this issue, and the fix proposed in this PR worked for me, tdhock/atime@d3d6220