chore: fix ruff linting and mypy issues in knowledge module

src/crewai/knowledge/source/base_knowledge_source.py

@@ -1,5 +1,5 @@
 from abc import ABC, abstractmethod
-from typing import Any, Dict, List, Optional
+from typing import Any
 
 import numpy as np
 from pydantic import BaseModel, ConfigDict, Field
@@ -12,29 +12,27 @@ class BaseKnowledgeSource(BaseModel, ABC):
 
     chunk_size: int = 4000
     chunk_overlap: int = 200
-    chunks: List[str] = Field(default_factory=list)
-    chunk_embeddings: List[np.ndarray] = Field(default_factory=list)
+    chunks: list[str] = Field(default_factory=list)
+    chunk_embeddings: list[np.ndarray] = Field(default_factory=list)
 
     model_config = ConfigDict(arbitrary_types_allowed=True)
-    storage: Optional[KnowledgeStorage] = Field(default=None)
-    metadata: Dict[str, Any] = Field(default_factory=dict)  # Currently unused
-    collection_name: Optional[str] = Field(default=None)
+    storage: KnowledgeStorage | None = Field(default=None)
+    metadata: dict[str, Any] = Field(default_factory=dict)  # Currently unused
+    collection_name: str | None = Field(default=None)
 
     @abstractmethod
     def validate_content(self) -> Any:
         """Load and preprocess content from the source."""
-        pass
 
     @abstractmethod
     def add(self) -> None:
         """Process content, chunk it, compute embeddings, and save them."""
-        pass
 
-    def get_embeddings(self) -> List[np.ndarray]:
+    def get_embeddings(self) -> list[np.ndarray]:
         """Return the list of embeddings for the chunks."""
         return self.chunk_embeddings
 
-    def _chunk_text(self, text: str) -> List[str]:
+    def _chunk_text(self, text: str) -> list[str]:
         """Utility method to split text into chunks."""
         return [
             text[i : i + self.chunk_size]