summarise what's new in swift 6?

Swift 6 introduces several new features and improvements aimed at enhancing safety, performance, and developer productivity. Here are some of the key updates:

1. Data Race Safety: Swift 6 introduces a new language mode that provides compile-time data race safety. This feature helps diagnose concurrent access to memory, making concurrent programming safer and more reliable. The new language mode is opt-in, allowing developers to adopt it at their own pace (Platforms State of the Union).

2. Non-Copyable Types: Swift 6 introduces non-copyable types, which suppress the default copyability of Swift types. This is useful for scenarios requiring unique ownership, such as managing system resources like files (What’s new in Swift).

3. Embedded Swift: A new language subset called Embedded Swift is introduced, allowing Swift to run on highly constrained systems like operating system kernels and microcontrollers. This expands Swift's applicability to more environments (What’s new in Swift).

4. Concurrency Improvements: Swift 6 continues to enhance concurrency features, making it easier to write safe and efficient concurrent code. This includes improvements to async/await and actor models (Platforms State of the Union).

5. Swift Testing Framework: A new testing framework named Swift Testing is introduced, providing expressive APIs to simplify writing tests (Platforms State of the Union).

6. GitHub Organization: Swift is moving to a new organization on GitHub, named swiftlang, which will host critical projects for the Swift ecosystem (What’s new in Swift).

These updates reflect Swift's ongoing evolution to meet modern development challenges while maintaining its focus on safety and performance.