Use pkgutil.ImpLoader instead of a custom loader for cubes import redirection It just works fine (same implementation of load_module method as _CubesLoader introduced in d404fd8499dd) and is complete w.r.t. PEP 302 (all methods implemented). Related to #13001466.

[check-manifest]
ignore =
  debian
  debian/*
  cubicweb.spec
  __pkginfo__.py