SR-3771 and SR-3751: libdispatch dependency on libkqueue
SR-3771 and SR-3751: libdispatch dependency on libkqueue

Revert back to libkqueue version that has the fix for
SR-2941 but does not have the changes to remove the
autotools-based build system.

apple/swift-corelibs-libdispatch,apple/swift-corelibs-libdispatch,apple/swift-corelibs-libdispatch,apple/swift-corelibs-libdispatch