fix: Lack of import constants

Use constants in contrib but lack of import it.
Here we import constants from skyline_apiserver.types to fix it.

Closes-Bug: #1942087
Change-Id: I6fd874400f77e9d201d6c5d7284c78345d52b63f

libs/skyline-apiserver/skyline_apiserver/api/v1/contrib.py

@@ -25,6 +25,7 @@ from skyline_apiserver.client.openstack import system
 from skyline_apiserver.client.openstack.system import get_endpoints
 from skyline_apiserver.config import CONF
 from skyline_apiserver.schemas import common
+from skyline_apiserver.types import constants
 
 router = APIRouter()