Chroe: some misc cleanup (#23203)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/core/ops/ops_trace_manager.py

         :return:
         """
         # auth check
-        if enabled == True:
+        if enabled:
             try:
                 provider_config_map[tracing_provider]
             except KeyError:

api/core/tools/builtin_tool/providers/time/tools/timezone_conversion.py

         target_time = self.timezone_convert(current_time, current_timezone, target_timezone)  # type: ignore
         if not target_time:
             yield self.create_text_message(
-                f"Invalid datatime and timezone: {current_time},{current_timezone},{target_timezone}"
+                f"Invalid datetime and timezone: {current_time},{current_timezone},{target_timezone}"
             )
             return
 

api/core/workflow/nodes/document_extractor/node.py

 
         for i in range(1, len(raw_results)):
             spk, txt = raw_results[i]
-            if spk == None:
+            if spk is None:
                 merged_results.append((None, current_text))
                 continue
 

api/core/workflow/nodes/llm/node.py

 import json
 import logging
 from collections.abc import Generator, Mapping, Sequence
-from typing import TYPE_CHECKING, Any, Optional, cast
+from typing import TYPE_CHECKING, Any, Optional
 
 from core.app.entities.app_invoke_entities import ModelConfigWithCredentialsEntity
 from core.file import FileType, file_manager
     UserPromptMessage,
 )
 from core.model_runtime.entities.model_entities import (
-    AIModelEntity,
     ModelFeature,
     ModelPropertyKey,
     ModelType,
 )
-from core.model_runtime.model_providers.__base.large_language_model import LargeLanguageModel
 from core.model_runtime.utils.encoders import jsonable_encoder
 from core.prompt.entities.advanced_prompt_entities import CompletionModelPromptTemplate, MemoryConfig
 from core.prompt.utils.prompt_message_util import PromptMessageUtil
             )
         return saved_file
 
-    def _fetch_model_schema(self, provider: str) -> AIModelEntity | None:
-        """
-        Fetch model schema
-        """
-        model_name = self._node_data.model.name
-        model_manager = ModelManager()
-        model_instance = model_manager.get_model_instance(
-            tenant_id=self.tenant_id, model_type=ModelType.LLM, provider=provider, model=model_name
-        )
-        model_type_instance = model_instance.model_type_instance
-        model_type_instance = cast(LargeLanguageModel, model_type_instance)
-        model_credentials = model_instance.credentials
-        model_schema = model_type_instance.get_model_schema(model_name, model_credentials)
-        return model_schema
-
     @staticmethod
     def fetch_structured_output_schema(
         *,