internal: Require rust 1.81

[darichey]

rust-analyzer doesn't build on 1.80 because we use #[expect(lint)]:

error[E0658]: the `#[expect]` attribute is an experimental feature
  --> crates/hir-expand/src/prettify_macro_expansion_.rs:11:1
   |
11 | #[expect(deprecated)]
   | ^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #54503 <https://github.com/rust-lang/rust/issues/54503> for more information

[lnicola]

@ChayimFriedman2 think we can switch that to allow? 1.81 is still relatively recent, and we've had complaints before. Also, is the trailing _ intended?

[ChayimFriedman2]

@ChayimFriedman2 think we can switch that to allow? 1.81 is still relatively recent, and we've had complaints before

I thought our policy is to support latest stable version, but if this is a problem, yes we can switch that to #[allow].

Also, is the trailing _ intended?

Yes, it's because we import the function with the same name from the module (and only export it), so they need to have different names.

[lnicola]

I thought our policy is to support latest stable version

On paper yes, but we're been less strict in the past. But I guess it's been three days and nobody complained yet so..

@bors r+

[bors]

📌 Commit 0536f18 has been approved by lnicola

It is now in the queue for this repository.

[bors]

⌛ Testing commit 0536f18 with merge af9a658...

[bors]

☀️ Test successful - checks-actions
Approved by: lnicola
Pushing af9a658 to master...