LDEV-5025,
LDEV-5120 Softly remove duplicate rating criteria
For Assessment and Dokumaran we only allow one rating criterion each. On
high load, after a gate was opened, there is a chance that 2 learners
will detect no criteria and both will create one, resulting a duplicate
criterion. Instead of throwing a hard exception and rendering the
activity unusable, just remove the duplicate criterion ignoring any
exceptions. This is lighter than having a multi-node synchronization.
