chore: enable F821, F401, W293 (#9503)

* auto fixes

* auto fix pt2 and transitive deps and undefined var checking locals()

* manual fixes (ignored or letta-code fixed)

* fix circular import

tests/test_provider_trace_summarization.py

@@ -11,7 +11,6 @@ from unittest.mock import AsyncMock, MagicMock, patch
 import pytest
 
 from letta.schemas.agent import AgentState
-from letta.schemas.block import Block
 from letta.schemas.embedding_config import EmbeddingConfig
 from letta.schemas.enums import MessageRole
 from letta.schemas.llm_config import LLMConfig