My workflow is stumbling over the keyword `nonisolated(unsafe)`, which IIRC was introduced with 5.10, but my test runner runs on 5.9.2. It fetches the version 1.26.0, which has declared 5.9 as its swift tools version. E. g. it will be used in [HTTPClient+HTTPCookie.swift](https://github.com/swift-server/async-http-client/blob/main/Sources/AsyncHTTPClient/HTTPClient%2BHTTPCookie.swift) on L219.