As per title, tracking task to consider providing Bullseye images ahead of official release. TTBOMK the base puppetization should work out of the box on Bullseye already (T275873)
UPDATE: To add project access:
openstack image add project f99ec8f1-f7e7-4a8d-95c8-45f49a5fea37 OS_PROJECT_ID=mediawiki-vagrant openstack image set --accept f99ec8f1-f7e7-4a8d-95c8-45f49a5fea37