This is how I make backups of Mediawikis on the web for archive.org.

I use wikiteam dump tools, commit 23efbefda888017c6399060b4647b64c035c6ffe which dates from 2017 but a more recent HEAD was broken when I last tried it. (I should try again).

Command:

python dumpgenerator.py --xml --images \
  --api https://www.nin.wiki/api.php \
  https://nin.wiki

Post-processing:

zip -r images.zip images
(find a suitable index image from images and move to the root)
trash images/

Uploading using the ia command line tool:

ia upload collection_name \
   --metadata="mediatype:text" \
   --metadata="collection:opensource" *

Where collection_name has been pre-created.