chore: remove unused import

Author: fdefelici

stacks-node/src/tests/signer/v0.rs

@@ -104,7 +104,6 @@ use tracing_subscriber::prelude::*;
 use tracing_subscriber::{fmt, EnvFilter};
 
 use super::SignerTest;
-use crate::burnchains::bitcoin_regtest_controller::BitcoinRPCRequest;
 use crate::event_dispatcher::{
     EventObserver, MinedNakamotoBlockEvent, TEST_SKIP_BLOCK_ANNOUNCEMENT,
 };