upload-pages-artifact is capped at v3

Author: coatless

.github/workflows/altdoc.yaml

@@ -101,7 +101,7 @@ jobs:
       # Make sure to set a retention day to avoid running into a cap
       # This artifact shouldn't be required after deployment onto pages was a success.
       - name: Upload Pages artifact
-        uses: actions/upload-pages-artifact@v4
+        uses: actions/upload-pages-artifact@v3
         with: 
           retention-days: 1