Change workflow to R-CMD-check-hard (i.e. a noSuggests check)

.github/workflows/R-CMD-check.yaml

@@ -1,16 +1,18 @@
 # Workflow derived from https://github.com/r-lib/actions/tree/v2/examples
 # Need help debugging build failures? Start at https://github.com/r-lib/actions#where-to-find-help
 #
-# NOTE: This workflow is overkill for most R packages and
-# check-standard.yaml is likely a better choice.
-# usethis::use_github_action("check-standard") will install it.
+# NOTE: This workflow only directly installs "hard" dependencies, i.e. Depends,
+# Imports, and LinkingTo dependencies. Notably, Suggests dependencies are never
+# installed, with the exception of testthat, knitr, and rmarkdown. The cache is
+# never used to avoid accidentally restoring a cache containing a suggested
+# dependency.
 on:
   push:
     branches: [main, master]
   pull_request:
     branches: [main, master]
 
-name: R-CMD-check
+name: R-CMD-check-hard
 
 jobs:
   R-CMD-check:
@@ -54,7 +56,13 @@ jobs:
 
       - uses: r-lib/actions/setup-r-dependencies@v2
         with:
-          extra-packages: any::rcmdcheck
+          dependencies: '"hard"'
+          cache: false
+          extra-packages: |
+            any::rcmdcheck
+            any::testthat
+            any::knitr
+            any::rmarkdown
           needs: check
 
       - uses: r-lib/actions/check-r-package@v2