Add --as-cran arg

Author: villegar

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

@@ -48,4 +48,4 @@ jobs:
       - uses: r-lib/actions/check-r-package@v2
         with:
           upload-snapshots: true
-          build_args: 'c("--no-manual","--compact-vignettes=gs+qpdf")'
+          build_args: 'c("--no-manual", "--as-cran", "--compact-vignettes=gs+qpdf")'