chore: checkpoint before Python removal

vendor/async-trait/tests/ui/send-not-implemented.rs

@@ -0,0 +1,22 @@
+use async_trait::async_trait;
+use std::sync::Mutex;
+
+async fn f() {}
+
+#[async_trait]
+trait Test {
+    async fn test(&self) {
+        let mutex = Mutex::new(());
+        let _guard = mutex.lock().unwrap();
+        f().await;
+    }
+
+    async fn test_ret(&self) -> bool {
+        let mutex = Mutex::new(());
+        let _guard = mutex.lock().unwrap();
+        f().await;
+        true
+    }
+}
+
+fn main() {}