[ty] Add support for @warnings.deprecated (astral-sh#19376)

* [x] basic handling
  * [x] parse and discover `@warnings.deprecated` attributes
  * [x] associate them with function definitions
  * [x] associate them with class definitions
  * [x] add a new "deprecated" diagnostic
* [x] ensure diagnostic is styled appropriately for LSPs
(DiagnosticTag::Deprecated)

* [x] functions
  * [x] fire on calls
  * [x] fire on arbitrary references 
* [x] classes
  * [x] fire on initializers
  * [x] fire on arbitrary references
* [x] methods
  * [x] fire on calls
  * [x] fire on arbitrary references
* [ ] overloads
  * [ ] fire on calls
  * [ ] fire on arbitrary references(??? maybe not ???)
  * [ ] only fire if the actual selected overload is deprecated 

* [ ] dunder desugarring (warn on deprecated `__add__` if `+` is
invoked)
* [ ] alias supression? (don't warn on uses of variables that deprecated
items were assigned to)

* [ ] import logic
  * [x] fire on imports of deprecated items
* [ ] suppress subsequent diagnostics if the import diagnostic fired (is
this handled by alias supression?)
  * [x] fire on all qualified references (`module.mydeprecated`)
  * [x] fire on all references that depend on a `*` import
    


Fixes astral-sh/ty#153

Author: Gankra

crates/ruff_benchmark/benches/ty.rs

@@ -527,14 +527,21 @@ impl<'a> ProjectBenchmark<'a> {
 
 #[track_caller]
 fn bench_project(benchmark: &ProjectBenchmark, criterion: &mut Criterion) {
-    fn check_project(db: &mut ProjectDatabase, max_diagnostics: usize) {
+    fn check_project(db: &mut ProjectDatabase, project_name: &str, max_diagnostics: usize) {
         let result = db.check();
         let diagnostics = result.len();
 
-        assert!(
-            diagnostics <= max_diagnostics,
-            "Expected <={max_diagnostics} diagnostics but got {diagnostics}"
-        );
+        if diagnostics > max_diagnostics {
+            let details = result
+                .into_iter()
+                .map(|diagnostic| diagnostic.concise_message().to_string())
+                .collect::<Vec<_>>()
+                .join("\n  ");
+            assert!(
+                diagnostics <= max_diagnostics,
+                "{project_name}: Expected <={max_diagnostics} diagnostics but got {diagnostics}:\n  {details}",
+            );
+        }
     }
 
     setup_rayon();
@@ -544,7 +551,7 @@ fn bench_project(benchmark: &ProjectBenchmark, criterion: &mut Criterion) {
     group.bench_function(benchmark.project.config.name, |b| {
         b.iter_batched_ref(
             || benchmark.setup_iteration(),
-            |db| check_project(db, benchmark.max_diagnostics),
+            |db| check_project(db, benchmark.project.config.name, benchmark.max_diagnostics),
             BatchSize::SmallInput,
         );
     });
@@ -612,7 +619,7 @@ fn datetype(criterion: &mut Criterion) {
             max_dep_date: "2025-07-04",
             python_version: PythonVersion::PY313,
         },
-        0,
+        2,
     );
 
     bench_project(&benchmark, criterion);