On a site hosted by OVH it is possible to have several versions of php depending on the use by using the multi-sites

(sub-domains)

OVH for multi_sites uses the .ovhconfig file:

  1. the root of the multi-site
  2. if not from the common file under the $HOME

The extension   SemantiMediaWiki is not currently compatible with php 8.1,

I kept version 7.4 for this subdomain   MediaWiki

 www/MediaWiki/.ovhconfig

environment=development
app.engine=php
http.firewall=none
container.image=stable64
app.engine.version=7.4