Fix plain_output for tests

tests/conftest.py

@@ -10,6 +10,7 @@ from autogpt.agent.agent import Agent
 from autogpt.config import AIConfig, Config, ConfigBuilder
 from autogpt.config.ai_config import AIConfig
 from autogpt.llm.api_manager import ApiManager
+from autogpt.logs import logger
 from autogpt.memory.vector import get_memory
 from autogpt.models.command_registry import CommandRegistry
 from autogpt.prompts.prompt import DEFAULT_TRIGGERING_PROMPT
@@ -52,6 +53,9 @@ def config(
     if not os.environ.get("OPENAI_API_KEY"):
         os.environ["OPENAI_API_KEY"] = "sk-dummy"
 
+    # HACK: this is necessary to ensure PLAIN_OUTPUT takes effect
+    logger.config = config
+
     config.plugins_dir = "tests/unit/data/test_plugins"
     config.plugins_config_file = temp_plugins_config_file