cubicweb-pyramid #5576180 pkg: add python-waitress dependency [validation pending]

because of import waitress in ccplugin.py

prioritynormal
typebug
done in0.3.0
load0.200
load left0.000
closed by#00bec1345a78 [pkg] depends on waitress (closes #5576180)
patch[pkg] depends on waitress (closes #5576180) [applied]