Update rhub.yaml

Author: JiscaH

.github/workflows/rhub.yaml

@@ -52,6 +52,7 @@ jobs:
 
     steps:
       - uses: r-hub/actions/checkout@v1
+      - uses: r-lib/actions/setup-tinytex@v2
       - uses: r-hub/actions/platform-info@v1
         with:
           token: ${{ secrets.RHUB_TOKEN }}
@@ -77,6 +78,7 @@ jobs:
 
     steps:
       - uses: r-hub/actions/checkout@v1
+      - uses: r-lib/actions/setup-tinytex@v2
       - uses: r-hub/actions/setup-r@v1
         with:
           job-config: ${{ matrix.config.job-config }}