chore: add the use keyword to impl Trait return types in preparation for Rust 2024.

Rust 2024 requires that you specify the generic parameters that are captured by the hidden type represented by `impl Trait`.

https://doc.rust-lang.org/std/keyword.use.html#precise-capturing

Author: plusvic

ls/src/utils/cst_traversal.rs

@@ -306,7 +306,7 @@ pub fn idents_declared_by_expr(
 /// Finds all identifiers declared by a `with` expression.
 pub fn idents_declared_by_with(
     with_expr: &Node<Immutable>,
-) -> impl Iterator<Item = Token<Immutable>> {
+) -> impl Iterator<Item = Token<Immutable>> + use<> {
     assert_eq!(with_expr.kind(), SyntaxKind::WITH_EXPR);
 
     with_expr
@@ -331,7 +331,7 @@ pub fn idents_declared_by_with(
 /// Finds all identifiers declared by a `for` expression.
 pub fn idents_declared_by_for(
     for_expr: &Node<Immutable>,
-) -> impl Iterator<Item = Token<Immutable>> {
+) -> impl Iterator<Item = Token<Immutable>> + use<> {
     assert_eq!(for_expr.kind(), SyntaxKind::FOR_EXPR);
     for_expr
         .children_with_tokens()