fix: remove unused tests

tests/handler_hello_test.rs

@@ -1,10 +0,0 @@
-#[cfg(test)]
-mod tests {
-    use rustysearch::handler::hello::say_hello;
-    
-    #[tokio::test]
-    async fn test_say_hello() {
-        let result = say_hello().await;
-        assert_eq!(result, "Hello, World!");
-    }
-}