Fix warnings for cloning references in generated code (#1676)

axum-macros/tests/from_ref/pass/reference-types.rs

@@ -0,0 +1,10 @@
+#![deny(noop_method_call)]
+
+use axum_macros::FromRef;
+
+#[derive(FromRef)]
+struct State {
+    inner: &'static str,
+}
+
+fn main() {}