chore: add ast-grep rule to convert Optional[T] to T | None (#25560)

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

api/configs/middleware/vdb/milvus_config.py

@@ -1,5 +1,3 @@
-from typing import Optional
-
 from pydantic import Field
 from pydantic_settings import BaseSettings
 
@@ -9,22 +7,22 @@ class MilvusConfig(BaseSettings):
     Configuration settings for Milvus vector database
     """
 
-    MILVUS_URI: Optional[str] = Field(
+    MILVUS_URI: str | None = Field(
         description="URI for connecting to the Milvus server (e.g., 'http://localhost:19530' or 'https://milvus-instance.example.com:19530')",
         default="http://127.0.0.1:19530",
     )
 
-    MILVUS_TOKEN: Optional[str] = Field(
+    MILVUS_TOKEN: str | None = Field(
         description="Authentication token for Milvus, if token-based authentication is enabled",
         default=None,
     )
 
-    MILVUS_USER: Optional[str] = Field(
+    MILVUS_USER: str | None = Field(
         description="Username for authenticating with Milvus, if username/password authentication is enabled",
         default=None,
     )
 
-    MILVUS_PASSWORD: Optional[str] = Field(
+    MILVUS_PASSWORD: str | None = Field(
         description="Password for authenticating with Milvus, if username/password authentication is enabled",
         default=None,
     )
@@ -40,7 +38,7 @@ class MilvusConfig(BaseSettings):
         default=True,
     )
 
-    MILVUS_ANALYZER_PARAMS: Optional[str] = Field(
+    MILVUS_ANALYZER_PARAMS: str | None = Field(
         description='Milvus text analyzer parameters, e.g., {"type": "chinese"} for Chinese segmentation support.',
         default=None,
     )