Fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: geoffw0

rust/ql/test/query-tests/security/CWE-327/WeakSensitiveDataHashing/test.rs

@@ -165,7 +165,7 @@ struct Seed {
 }
 
 impl Seed {
-    fn new(seed_value: u64) -> Self {
+    fn new(_seed_value: u64) -> Self {
         Seed { }
     }
 }