fix(test): use real ActionValidators instance in auth_processors fixture

MagicMock(spec=ActionValidators) fails because dataclass fields without
defaults are not in dir(cls), causing AttributeError on .rbac access.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: fregataa

tests/component/conftest.py

@@ -74,6 +74,7 @@
 from ai.backend.logging.config import ConsoleConfig, LogDriver, LoggingConfig
 from ai.backend.logging.types import LogFormat
 from ai.backend.manager.actions.validators import ActionValidators
+from ai.backend.manager.actions.validators.rbac import RBACValidators
 from ai.backend.manager.agent_cache import AgentRPCCache
 from ai.backend.manager.api import ManagerStatus
 from ai.backend.manager.api.rest.app import build_root_app, mount_registries
@@ -1187,7 +1188,9 @@ def auth_processors(
         config_provider=config_provider,
     )
     return AuthProcessors(
-        service=service, action_monitors=[], validators=MagicMock(spec=ActionValidators)
+        service=service,
+        action_monitors=[],
+        validators=ActionValidators(rbac=MagicMock(spec=RBACValidators)),
     )