[devtools] set .config in setUpClass instead of using a cache in a classproperty This is much clearer and avoid problem with py.test introspection that triggered creation and caching of the configuration before actual test execution. This caused pb in unittest_postgres.PostgresStatementTimeoutTC where configuration was built before module's setup, hence source configuration was missing information about where to find the pg cluster.

[devtools] Simplify test configuration's init Specify module's __file__ instead of apphome. __file__ is saved on the class as it will be used later (eg to find the proper pg cluster without relying on shared dictionnary modifications). This will require some tests update, but it should be less common in cubes than in cubicweb itself.

[web] Have the LoginController return 403 on failed auth (closes #11569950)

[devtools] Drop old init_test_database backward compat

[devtools] show DeprecationWarning during test execution They are not shown by default since python 2.7

[devtools] deprecate usage of sources file for test This is old support which clutters the code and should no more be used. As this is rarely used (if it is) and test only, it feels ok to drop support at once without a deprecation phase.