[entities, view] delete dead code
The auto_unwrap_bw_compat metaclass calls unwrap_adapter_compat, which
was removed in changeset 697a8181ba30 "remove 3.9 bw compat". So this
can't possibly work anymore, meaning we can get rid of it.
usr/lib/PY_VERSION/*-packages/cubicweb/server/
usr/lib/PY_VERSION/*-packages/cubicweb/hooks/
usr/lib/PY_VERSION/*-packages/cubicweb/sobjects/
usr/lib/PY_VERSION/*-packages/cubicweb/schemas/
usr/share/cubicweb/migration/