Fix GitHub Actions

[hutch3232]

To be honest I didn't really know what I was doing and feel I lucked out getting it to pass on the first try. I essentially just updated the action versions. I also added builds for pull requests. Open to any feedback, this was kind of just a test run that happened to (seemingly) work.

edit: spoke too soon, pkgdown failed, but I think that's expected because I don't have necessary permissions on the main repo.

[torfason]

Great! That really is how this should work, and increasingly does with the more recent versions of the actions and the added benefit of usethis simplifying integration. In other words, when the code is good the CI checks should work without fuss.

I'm sure you are right about the pkgdown scripts, that this is a permissions thing. I can update them to run at the appropriate time (not on PRs and not on all branches) as I finalize the release. The important thing is to have R-CMD-check passing on all platforms and versions. Hoping to get to this by the weekend, will be in touch if I see anything else.