Upgrade download-artifact action to v8

Fix deprecated warning when building with documentation

Author: williamchange

.github/workflows/dev-desktop-builds.yml

@@ -173,7 +173,7 @@ jobs:
           rm ./build/mac/material_maker.zip
       - name: Get documentation 🚀
         if: ${{ github.event.inputs.gen_doc == 'true' }}
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v8
         with:
           name: documentation
           path: doc