Update preview.yml

Author: lmichel

.github/workflows/preview.yml

@@ -32,7 +32,9 @@ jobs:
         sudo snap install pdftk
     
     - name: Build the document
-      run: make ${{ env.doc_name }}-draft.pdf
+      run: |
+        make forcetex
+        make ${{ env.doc_name }}-draft.pdf
     
     - name: Check the output
       run: |