Cancelling QUIC connection attempts fails

[kb-1000]

If you create a classic TCP connection using Bootstrap, you get a ChannelFuture that you can .cancel() before the connection is complete.
QuicChannelBootstrap gives you a Future<QuicChannel> instead, which you CAN also call the same .cancel() method on, but if you do, it won't actually cancel the attempt and will only fail to return the result:

[21:44:44] [Netty Epoll Client IO #0/WARN] (DefaultPromise) An exception was thrown by io.netty.incubator.codec.quic.QuicChannelBootstrap$$Lambda/0x00007f67380c6a88.operationComplete()
 java.lang.IllegalStateException: complete already: DefaultPromise@5b753206(failure: io.netty.util.concurrent.DefaultPromise$StacklessCancellationException)
	at knot/io.netty.util.concurrent.DefaultPromise.setFailure(DefaultPromise.java:113) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.incubator.codec.quic.QuicChannelBootstrap.lambda$null$0(QuicChannelBootstrap.java:236) ~[netty-incubator-codec-classes-quic-0.0.70.Final.jar:?]
	at knot/io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:590) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:583) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:559) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:492) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.DefaultPromise.setValue0(DefaultPromise.java:636) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.DefaultPromise.setFailure0(DefaultPromise.java:629) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:118) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.incubator.codec.quic.QuicheQuicChannel$QuicChannelUnsafe.lambda$connect$1(QuicheQuicChannel.java:1540) ~[netty-incubator-codec-classes-quic-0.0.70.Final.jar:?]
	at knot/io.netty.util.concurrent.PromiseTask.runTask(PromiseTask.java:98) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:156) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:173) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:166) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:408) ~[netty-transport-classes-epoll-4.1.115.Final.jar:?]
	at knot/io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) ~[netty-common-4.1.115.Final.jar:?]
	at knot/io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.115.Final.jar:?]
	at java.base/java.lang.Thread.run(Thread.java:1575) [?:?]
Caused by: io.netty.channel.ConnectTimeoutException: connection timed out: QuicConnectionAddress{EPHEMERAL}
	at knot/io.netty.incubator.codec.quic.QuicheQuicChannel$QuicChannelUnsafe.lambda$connect$1(QuicheQuicChannel.java:1539) ~[netty-incubator-codec-classes-quic-0.0.70.Final.jar:?]
	... 9 more

Some way to cancel this should exist. I haven't been able to cause this scenario yet (and I am not sure to what extent it makes sense?), but I imagine calling cancel on the Future<QuicStreamChannel> that QuicChannel.createStream() returns would behave similarly.