[CI] Switch to pak

[yutannihilation]

Fix #4424

Test build: https://github.com/yutannihilation/ggplot2/runs/2361972393

[thomasp85]

Thanks - there's a new GHA that uses pak and does all of this automatically, so we'll be migrating to that instead

[yutannihilation]

Hmm, yeah, using pak seems better. This pull request still fails to build the pkgdown site...

ERROR: dependencies ‘gtable’, ‘isoband’, ‘scales’ are not available for package ‘ggplot2’

[yutannihilation]

Switched to pak and this seems to work.

https://github.com/yutannihilation/ggplot2/runs/2362084213

[thomasp85]

Since you are as far as I am and have a better feeling for the CI scripts do you mind updating all the scripts to use pak, i.e. run usethis::use_tidy_github_actions() with the dev version of usethis and make sure to not remove stuff we have added?

[yutannihilation]

Oh, sure. I will.

[yutannihilation]

It seems pak::pkg_deps() doesn't work when there's unavailable packages. We need to fix pak first...

[yutannihilation]

It turned out pak is not quite ready to use in our repo. I'll think if we can add some (probably not very simple) workaround or give up for now.

[thomasp85]

Ok, let's just fix the pkgdown build for now then... will you roll back the last commits?

[yutannihilation]

Reverted. I'll file a new issue for migrating R-CMD-check.yaml to pak when it's ready.