upgrade pulsar dependency to 2.8.0-rc-202105251229

[hangc0276]

Motivation

When running KoP on Pulsar build by 2.8.0-rc-202105202205 or later, it will throw the following exception.

java.lang.NoSuchMethodError: org.apache.pulsar.broker.service.BrokerService.executor()Ljava/util/concurrent/ScheduledExecutorService;
        at io.streamnative.pulsar.handlers.kop.KafkaTopicManager.<init>(KafkaTopicManager.java:87) ~[?:?]
        at io.streamnative.pulsar.handlers.kop.KafkaRequestHandler.<init>(KafkaRequestHandler.java:246) ~[?:?]
        at io.streamnative.pulsar.handlers.kop.KafkaChannelInitializer.initChannel(KafkaChannelInitializer.java:92) ~[?:?]
        at io.streamnative.pulsar.handlers.kop.KafkaChannelInitializer.initChannel(KafkaChannelInitializer.java:34) ~[?:?]
        at io.netty.channel.ChannelInitializer.initChannel(ChannelInitializer.java:129) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.ChannelInitializer.handlerAdded(ChannelInitializer.java:112) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.AbstractChannelHandlerContext.callHandlerAdded(AbstractChannelHandlerContext.java:938) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.DefaultChannelPipeline.callHandlerAdded0(DefaultChannelPipeline.java:609) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.DefaultChannelPipeline.access$100(DefaultChannelPipeline.java:46) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.DefaultChannelPipeline$PendingHandlerAddedTask.execute(DefaultChannelPipeline.java:1463) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.DefaultChannelPipeline.callHandlerAddedForAllHandlers(DefaultChannelPipeline.java:1115) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.DefaultChannelPipeline.invokeHandlerAddedIfNeeded(DefaultChannelPipeline.java:650) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.AbstractChannel$AbstractUnsafe.register0(AbstractChannel.java:514) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.AbstractChannel$AbstractUnsafe.access$200(AbstractChannel.java:429) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.AbstractChannel$AbstractUnsafe$1.run(AbstractChannel.java:486) [io.netty-netty-transport-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164) [io.netty-netty-common-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472) [io.netty-netty-common-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:384) [io.netty-netty-transport-native-epoll-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989) [io.netty-netty-common-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) [io.netty-netty-common-4.1.63.Final.jar:4.1.63.Final]
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [io.netty-netty-common-4.1.63.Final.jar:4.1.63.Final]

It was cause by apache/pulsar#2603, which changed the brokerService.executor() interface from ScheduledExecutorService to EventLoopGroup.

Modification

upgrade Pulsar dependency to 2.8.0-rc-202105251229 and resolve the exception.