cubicweb #5457566 cwuri should be a read-only attribute [validation pending]

allowing modification of this attribute is dangerous wrt multi-source handling

prioritynormal
typebug
done in3.20.8
load0.500
load left0.000
closed by#82071f767cb8 [schemas] cwuri should be read-only
patch[schemas] cwuri should be read-only [applied]