Auto merge of #119042 - bvanjoi:fix-118697-2, r=compiler-errors

fallback `default` to `None` during ast-lowering for lifetime binder

Fixes #118697

This is another attempt. It has a fallback, setting `default` to `None` and emit an error for non-lifetime binders during ast lowering.

r? `@compiler-errors`

Author: bors