cubicweb #7023315 stop deleting data using rql on schema upgrade [validation pending]

In most case when we want to drop some entity/relation, we don't care of hooks being called on their deletion. There is even low chances that some hooks still exists, based on an old version of the schema. Last but not least, this is at best mostly inefficient.

prioritynormal
typeenhancement
done in3.22.0
load2.000
load left0.000
closed by#977def81780a [migration] don't handle data deletion anymore on schema changes
patch[migration] don't handle data deletion anymore on schema changes [applied]