Allow dead_code for checkpoint::Verifier for now

zebra-consensus/src/checkpoint.rs

@@ -143,6 +143,7 @@ where
     /// than constructing multiple verification services for the same network. To
     /// clone a CheckpointVerifier, you might need to wrap it in a
     /// `tower::Buffer` service.
+    #[allow(dead_code)]
     pub fn new(
         network: Network,
         initial_tip: Option<(block::Height, block::Hash)>,