Install rtools4

Author: jeroen

.github/workflows/bundle.yml

@@ -12,7 +12,8 @@ jobs:
           git config --global core.autocrlf false
           git config --global user.email 'jeroenooms@gmail.com'
           git config --global user.name  'Jeroen Ooms (via CI)'
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
+      - uses: r-windows/install-rtools@master
       - id: download
         name: Download libraries
         run: |