Update R-CMD-check.yaml

Author: jgabry

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

@@ -48,5 +48,5 @@ jobs:
       - uses: r-lib/actions/check-r-package@v2
         with:
           upload-snapshots: true
-          args: 'c("--ignore-vignettes")'
+          args: 'c("--ignore-vignettes", "--no-manual")'
           build_args: 'c("--no-manual", "--no-build-vignettes")'