Workflow update for R CMD Check

We currently test on the current release of R, the last version, and the dev version. Looking around here you'd think Sure, she's got everything...but I want more 🎶

• I want to run R CMD Check on the last 4 releases of R (this is something gtsummary has committed to in the past). There are things that need to be addressed for this:
  1. Some of the suggested deps will not be available for older versions of R. This is fine, but {pak} will error if any of the packages are not available. So we need to address that error
  2. There is an option to not error in R CMD Check when a Suggsted dep is not available. Need to find the correct flag/option to use. It's not --nosuggest.
• We currently use the base R placeholder syntax (e.g. 1:10 |> mean(x = _)) in just one or two places. once we have our checks working on older versions of R, we can replace that syntax with magrittr pipe code and we can then support R 4.1 (instead of 4.2, where we are currently set at)