Links generated in rustdoc is broken

[Xuanwo]

In https://opendal.apache.org/docs/rust/opendal/struct.Operator.html, we have

But we expect:

---

This can't be reproduced locally.

[Xuanwo]

The error message itself is wrong:

warning: unresolved link to `Operator::Operator`
  --> core/src/types/operator/operator.rs:42:66
   |
42 | /// Read [`Operator::concepts`][docs::concepts] for more about [`Operator::Operator`].
   |                                                                  ^^^^^^^^^^^^^^^^^^ the struct `Operator` has no field or associated item named `Operator`
   |
   = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: unresolved link to `Operator::services`
  --> core/src/types/operator/operator.rs:46:42
   |
46 | /// Read more backend init examples in [`Operator::services`]
   |                                          ^^^^^^^^^^^^^^^^^^ the struct `Operator` has no field or associated item named `services`

warning: unresolved link to `Operator::Lister`

[Xuanwo]

Fixed by upgrading rust toolchain.