Drop 3.13 incomplete backward compat in edit controller. It is very old and broken (there is another non-backward-copmpatible usage of `_cw_entity_fields`), better to remove it instead of fixing. Closes #3515223.

missing-dep-for-interpreter make => make | build-essential | dpkg-dev (usr/share/pyshared/cubicweb/skeleton/debian/rules.tmpl)