fix(ci): gate WFP service hashing imports to Windows

Signed-off-by: oscarmackjr-twg <oscar.mack.jr@gmail.com>

Author: oscarmackjr-twg

crates/nono-cli/src/bin/nono-wfp-service.rs

@@ -8,7 +8,6 @@
 #[path = "../windows_wfp_contract.rs"]
 mod windows_wfp_contract;
 
-use sha2::{Digest, Sha256};
 use std::io::Read;
 use std::process::ExitCode;
 use windows_wfp_contract::{
@@ -21,6 +20,9 @@ const PROBE_RUNTIME_ACTIVATION_ARG: &str = "--probe-runtime-activation";
 const EXPECTED_DRIVER_BINARY: &str = "nono-wfp-driver.sys";
 const MAX_RUNTIME_REQUEST_SIZE: usize = 64 * 1024;
 
+#[cfg(target_os = "windows")]
+use sha2::{Digest, Sha256};
+
 #[cfg(target_os = "windows")]
 use std::os::windows::ffi::OsStrExt;