Strict concurrency for NIOHTTP1Tests

[glbrntt]

No description provided.

[rnro]

It looks like there are still outstanding concurrency issues

/swift-nio/Tests/NIOHTTP1Tests/TestUtils.swift:705:52: error: type 'FulfillOnFirstEventHandler' does not conform to the 'Sendable' protocol
441 | ///
442 | /// - Note: Once this is used more widely and shows value, we might want to put it into `NIOTestUtils`.
443 | final class FulfillOnFirstEventHandler: ChannelDuplexHandler {
    |             `- note: class 'FulfillOnFirstEventHandler' does not conform to the 'Sendable' protocol
444 |     typealias InboundIn = Any
445 |     typealias OutboundIn = Any
    :
703 |                     channel
704 |                 }.cascade(to: tcpAcceptedChannel)
705 |                 return channel.pipeline.addHandler(FulfillOnFirstEventHandler(channelActivePromise: accepted))
    |                                                    `- error: type 'FulfillOnFirstEventHandler' does not conform to the 'Sendable' protocol
706 |             }
707 |             .bind(to: bindTarget)

[glbrntt]

It looks like there are still outstanding concurrency issues

/swift-nio/Tests/NIOHTTP1Tests/TestUtils.swift:705:52: error: type 'FulfillOnFirstEventHandler' does not conform to the 'Sendable' protocol
441 | ///
442 | /// - Note: Once this is used more widely and shows value, we might want to put it into `NIOTestUtils`.
443 | final class FulfillOnFirstEventHandler: ChannelDuplexHandler {
    |             `- note: class 'FulfillOnFirstEventHandler' does not conform to the 'Sendable' protocol
444 |     typealias InboundIn = Any
445 |     typealias OutboundIn = Any
    :
703 |                     channel
704 |                 }.cascade(to: tcpAcceptedChannel)
705 |                 return channel.pipeline.addHandler(FulfillOnFirstEventHandler(channelActivePromise: accepted))
    |                                                    `- error: type 'FulfillOnFirstEventHandler' does not conform to the 'Sendable' protocol
706 |             }
707 |             .bind(to: bindTarget)

Oh, this is symlinked in from NIOPosixTests which I've been working on in a separate commit. I didn't retest locally when I broke things up per target which is why I missed this.