Fix: Ensure clear_auth_cookie uses the correct secure and samesite settings (#1959)

* Update cookie.py - Ensure clear_auth_cookie uses correct secure and samesite settings

Ensure clear_auth_cookie uses correct secure and samesite settings

clear_auth_cookie was not explicitly specifying the secure and samesite 
attributes when deleting cookies. This could cause logout issues if 
CHAINLIT_COOKIE_SAMESITE was set to a custom value. 

Now, clear_auth_cookie applies the same secure and samesite settings 
as set_auth_cookie to ensure consistent behavior.

* Update cookie.py

fix format

Author: ilkertuna

backend/chainlit/auth/cookie.py

@@ -149,7 +149,9 @@ def set_auth_cookie(request: Request, response: Response, token: str):
 
     # Delete remaining prior cookies/cookie chunks
     for k in existing_cookies:
-        response.delete_cookie(key=k, path="/")
+        response.delete_cookie(
+            key=k, path="/", secure=_cookie_secure, samesite=_cookie_samesite
+        )
 
 
 def clear_auth_cookie(request: Request, response: Response):
@@ -162,7 +164,9 @@ def clear_auth_cookie(request: Request, response: Response):
     }
 
     for k in existing_cookies:
-        response.delete_cookie(key=k, path="/")
+        response.delete_cookie(
+            key=k, path="/", secure=_cookie_secure, samesite=_cookie_samesite
+        )
 
 
 def set_oauth_state_cookie(response: Response, token: str):