Unexpected behaviour with nullish coalesce on UUID cast to object with top-level query parameter

[Sikarii]

• EdgeDB Version: 5.2+ddd8aa4
• EdgeDB CLI Version: 5.1.0+fdf5320
• OS Version: N/A

Steps to Reproduce:

1. Run query below
2. Observe that bad returns an empty set, despite the nullish coalesce

with
  id := <optional uuid>$id # Not provided via params
select {
  bad := <Item>id ?? <Item><uuid>"54f54828-08ce-11ef-9f4b-03801670d1a7",
  good := <Item><optional uuid>$id ?? <Item><uuid>"54f54828-08ce-11ef-9f4b-03801670d1a7"
};