Fixing path of ABC

harvester/endpoint/__init__.py

 from typing import Optional
 
+from ..abc import Endpoint
 from .oads import OADSEndpoint
 from .ogcapi import OGCAPIEndpoint
 from .opensearch import OpenSearchEndpoint
 from .stacapi import STACAPIEndpoint
-from ._endpoint import Endpoint
 
 ENDPOINT_MAP = {
     "OADS": OADSEndpoint,