* save progress
* Replace `TransactionBody` with `NIOAsyncSequenceProducer`
* test
* revert unnesscary changes
* Add end-to-end test
which currently fails because of https://github.com/apple/swift-nio/issues/2398
* soundness
* Use latest swift-nio release
* throw CancellationError on task cancelation
* Fix Swift 5.5 & 5.6
* Tollerate more data after request body is cancelled
* wait is not needed if we shutdown the server first
* Remove test that depends on external resources
* Remove unused conformance to Equatable
* SwiftFormat
* run generate_linux_tests.rb
* Increase timeout for CI
### Motivation
With Xcode 13.2, and therefore Swift 5.5.2, Swift Concurrecy is supported on older Apple OSs. async/await suport will no longer be available on Swift before `5.5.2` but this isn't a breaking change because we have not yet made anything of it public.
### Changes
- replace all `#if compiler(>=5.5) && canImport(_Concurrency)` with `#if compiler(>=5.5.2) && canImport(_Concurrency)`
- replace all `available(macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0, *)` with `available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)`