Add remaining missing imports

Sources/NIOTransportServices/StateManagedNWConnectionChannel.swift

@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #if canImport(Network)
+import Atomics
 import Foundation
 import NIOCore
 import NIOConcurrencyHelpers

Tests/NIOTransportServicesTests/NIOTSConnectionChannelTests.swift

@@ -16,6 +16,7 @@
 import XCTest
 import Network
 import NIOCore
+import NIOFoundationCompat
 import NIOTransportServices
 import Foundation