Upgrade to tower-lsp 0.13.0

[ebkalderon]

See changes in release v0.13.0 for details!

Note: since all the Client methods have been changed to async fn, as described in ebkalderon/tower-lsp#180 (comment), I identified a compile error caused by tree-sitter interacting poorly with async/await and Send futures:

error: future cannot be sent between threads safely
  --> crates/server/src/lsp/api.rs:25:65
   |
25 |       async fn did_open(&self, params: DidOpenTextDocumentParams) {
   |  _________________________________________________________________^
26 | |         crate::service::synchronizer::document::open(self.session.clone(), params)
27 | |             .await
28 | |             .unwrap()
29 | |     }
   | |_____^ future returned by `__did_open` is not `Send`
   |
   = help: within `impl core::future::future::Future`, the trait `std::marker::Send` is not implemented for `*const std::ffi::c_void`
note: future is not `Send` as this value is used across an await
  --> crates/server/src/service/auditor.rs:95:13
   |
17 |             let node = tree.root_node();
   |                 ---- has type `tree_sitter::Node<'_>` which is not `Send`
...
95 |             session.client.publish_diagnostics(uri.clone(), diagnostics, version).await;
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ await occurs here, with `node` maybe used later
96 |         }
   |         - `node` is later dropped here
   = note: required for the cast to the object type `dyn core::future::future::Future<Output = ()> + std::marker::Send`

This is fixed by wrapping the node variable in a lexical scope so that the variable gets dropped early before the session.client.publish_diagnostics(...).await; call occurs. This solution was inspired by rust-lang/rust#64856.

Let me know what you think, @darinmorrison! Does this look good to you? Any suggestions?

[ebkalderon]

Force-pushed to fix formatting errors caught by CI.

[silvanshade]

Looks good to me. Thanks for the PR!

[ebkalderon]

No problem! Feel free to ping me if there are any further issues.