refactor: Import <|> in the Deserialize derive

tests/pass/serialization/de.glu

@@ -2,7 +2,6 @@ let result @ { Result, ? } = import! std.result
 let de @ { Deserializer, ValueDeserializer, Deserialize, field, deserializer, ? } = import! std.serialization.de
 let { Test, run, assert, assert_eq, test, group, ? }  = import! std.test
 let { Applicative, (*>) } = import! std.applicative
-let { (<|>) } = import! std.alternative
 let { map } = import! std.functor
 let { (<|) } = import! std.function
 let int = import! std.int
@@ -30,6 +29,7 @@ group "de" [
         assert_eq (de.deserialize deserializer r#"{ "record" : { "y" : "abc", "x" : 1 }, "y" : 1 } "#) (Ok { record = { x = 1 }, y = 1.0 }),
 
     group "alternative" (
+        let { (<|>) } = import! std.alternative
         let d : ValueDeserializer _ =
             de.int <|> map (\s -> result.unwrap_ok (int.parse s)) de.string
         [

vm/src/derive.rs

@@ -695,6 +695,7 @@ fn generate_deserialize(
     );
     let functor_import = generate_import(span, symbols, &[], &["map"], "std.functor");
     let applicative_import = generate_import(span, symbols, &[], &["<*>"], "std.applicative");
+    let alternative_import = generate_import(span, symbols, &[], &["<|>"], "std.alternative");
 
     let deserializer_binding = ValueBinding {
         name: pos::spanned(span, Pattern::Ident(deserializer_fn.clone())),
@@ -726,6 +727,7 @@ fn generate_deserialize(
         serialization_import,
         functor_import,
         applicative_import,
+        alternative_import,
         deserializer_binding,
     ].into_iter()
         .rev()