test: fix conftest setting of language

[no changelog]

tests/conftest.py

@@ -337,7 +337,9 @@ def client(
     if _raw_client.model is not models.T1B1:
         lang = request.session.config.getoption("lang") or "en"
         assert isinstance(lang, str)
-        translations.set_language(_raw_client, lang)
+        translations.set_language(
+            SessionDebugWrapper(_raw_client.get_management_session()), lang
+        )
 
     setup_params = dict(
         uninitialized=False,