[devtools] properly close open access on tearDown
avoiding further warning about living sessions while the repo is turned off.
The doc string says:
The RepoAccess need to be closed to destroy the associated Session.
TestCase usually take care of this aspect for the user.
but that wasn't true until now.
drop_relation_definition('CWSourceSchemaConfig', 'cw_schema', 'CWAttribute')
sync_schema_props_perms('cw_schema')