The Pywikibot framework contains the script wikisourcetext.py which creates Wikisource pages for an index including the OCR from the underlying PDF. Detail: https://github.com/wikimedia/pywikibot-core/blob/master/scripts/wikisourcetext.py
Although this script has a -force option it does not allow to recreate/overwrite such pages if they have been already created. However, this would be an important feature in cases when the underlying PDF has been modified.
The current workaround would require a cumbersome movement of pages or their deletion.