use BaseBackendError as type hint

Author: bisgaard-itis

services/api-server/src/simcore_service_api_server/exceptions/handlers/_handlers_backend_errors.py

@@ -12,7 +12,9 @@
 _logger = logging.getLogger(__name__)
 
 
-async def backend_error_handler(request: Request, exc: Exception) -> JSONResponse:
+async def backend_error_handler(
+    request: Request, exc: BaseBackEndError
+) -> JSONResponse:
     assert request  # nosec
     assert isinstance(exc, BaseBackEndError)
     user_error_msg = f"{exc}"