Change GH actions workflow to include dependencies for PDF rendering

.github/workflows/publish.yml

@@ -26,7 +26,7 @@ jobs:
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - name: Check out repository
-        uses: actions/checkout@v3
+        uses: actions/checkout
 
       # Runs a single command using the runners shell
       # - name: Run a one-line script
@@ -38,6 +38,13 @@ jobs:
       #     echo Add other actions to build,
       #     echo test, and deploy your project.
 
+      - name: Download R dependencies for rendering to PDF
+        uses: r-lib/actions/setup-r-dependencies@v2
+        with:
+          packages:
+            any::rmarkdown
+            any::knitr
+
       - name: Set up Quarto
         uses: quarto-dev/quarto-actions/setup@v2
         with: