model-derive: add derive attributes at start of list

Rust 1.52 added a legacy_derive_helpers warning (soon to be an error) that
yells if you use an attribute macro before the derive macro that introduces it.
We should always put derive macros at the start of the list to avoid this.

Reference: rust-lang/rust#79202

sources/models/model-derive/src/lib.rs

@@ -130,7 +130,10 @@ impl VisitMut for ModelHelper {
             } else {
                 parse_quote!(#[derive(Debug, PartialEq, Serialize, Deserialize)])
             };
-            node.attrs.push(attr);
+            // Rust 1.52 added a legacy_derive_helpers warning (soon to be an error) that yells if
+            // you use an attribute macro before the derive macro that introduces it.  We should
+            // always put derive macros at the start of the list to avoid this.
+            node.attrs.insert(0, attr);
         }
 
         // Let the default implementation do its thing, recursively.