fix error deleting server instances

cleanup.py

@@ -7,7 +7,7 @@ import os
 def main() -> None:
     conn = openstack.connect()
     for server in conn.compute.servers(name=env.VM_NAME):
-        conn.compute.delete_server(server, force=True)
+        conn.delete_server(server.id, wait=True, delete_ips=True)
     if os.path.exists(env.PRIVATE_KEY_PATH):
         os.remove(env.PRIVATE_KEY_PATH)
     conn.delete_keypair(env.KEY_PAIR_NAME)