Repair/Update pkgdown GitHub Action

[brookslogan]

No description provided.

[brookslogan]

The above checks don't tell use whether the pkgdown action is going to succeed (and the checks were already using @v2 actions). Going to just go ahead and merge to check if this repairs the site build. Might be good to explore, e.g., https://github.com/nektos/act, to see if there's a way to test locally in the future.