[utils] Drop now-unused SizeConstrainedList It's last usage in CubicWeb got removed from changeset '[views] remove breadcrumbs usage to retrieve last visited page' Related to #5456850.

usr/bin/cubicweb-ctl usr/bin/
usr/lib/python2*/*-packages/cubicweb/cwctl.py
../cubicweb-ctl.bash_completion etc/bash_completion.d/cubicweb-ctl