chore(cli): enhance empty updater key password warning (#6558)

tooling/cli/src/signer/generate.rs

@@ -31,7 +31,7 @@ pub fn command(mut options: Options) -> Result<()> {
   options.ci = options.ci || std::env::var("CI").is_ok();
 
   if options.ci && options.password.is_none() {
-    println!("Generating new private key without password.");
+    log::warn!("Generating new private key without password. For security reasons, we recommend setting a password instead.");
     options.password.replace("".into());
   }
   let keypair = generate_key(options.password).expect("Failed to generate key");