try an even older version

Author: Aurel300

.github/workflows/build.yaml

@@ -20,7 +20,7 @@ jobs:
     - name: Setup mdBook
       uses: peaceiris/actions-mdbook@v1
       with:
-        mdbook-version: "0.5.0"
+        mdbook-version: "0.4.52"
 
     - name: Generate tutorial
       run: |