Lower concurrency for WikiTrainingLoader mediawiki access
Lower concurrency for WikiTrainingLoader mediawiki access

We're getting lots of 429s, and can't reload training content.

WikiEducationFoundation/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard