ci: more packages

Author: m-muecke

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

@@ -50,6 +50,11 @@ jobs:
         env:
           TINYTEX_INSTALLER: TinyTeX
 
+      - name: Install additional LaTeX packages
+        run: |
+          tlmgr update --self
+          tlmgr install doublestroke relsize
+
       - uses: r-lib/actions/check-r-package@v2
         with:
           upload-snapshots: true