Made CSRF_COOKIE_SAMESITE fully optional, to support older Django.

Author: joshourisman

pydantic_settings/settings.py

@@ -258,7 +258,7 @@ class PydanticSettings(BaseSettings):
     CSRF_COOKIE_HTTPONLY: Optional[bool] = global_settings.CSRF_COOKIE_HTTPONLY
     CSRF_COOKIE_SAMESITE: Optional[
         Literal["Lax", "Strict", "None"]
-    ] = global_settings.CSRF_COOKIE_SAMESITE  # type: ignore
+    ] = _get_default_setting("CSRF_COOKIE_SAMESITE")  # type: ignore
     CSRF_HEADER_NAME: Optional[str] = global_settings.CSRF_HEADER_NAME
     CSRF_TRUSTED_ORIGINS: Optional[List[str]] = global_settings.CSRF_TRUSTED_ORIGINS
     CSRF_USE_SESSIONS: Optional[bool] = global_settings.CSRF_USE_SESSIONS