On main, `InboundHandlerTests.testLogsSlowInboundProcessing` throws the following exception during processing:

    java.lang.NullPointerException: Cannot read field "length" because "this.slice" is null
	    at org.elasticsearch.common.bytes.BytesReferenceStreamInput.readVInt(BytesReferenceStreamInput.java:83)
	    at org.elasticsearch.common.io.stream.FilterStreamInput.readVInt(FilterStreamInput.java:60)
	    at org.elasticsearch.common.io.stream.StreamInput.readArraySize(StreamInput.java:1307)
	    at org.elasticsearch.common.io.stream.StreamInput.readString(StreamInput.java:428)
	    at org.elasticsearch.tasks.TaskId.readFromStream(TaskId.java:70)
	    at org.elasticsearch.transport.TransportRequest.<init>(TransportRequest.java:37)
	    at org.elasticsearch.transport.TransportHandshaker$HandshakeRequest.<init>(TransportHandshaker.java:184)
	    at org.elasticsearch.transport.TransportHandshaker.handleHandshake(TransportHandshaker.java:89)
	    at org.elasticsearch.transport.InboundHandler.handleRequest(InboundHandler.java:218)
	    at org.elasticsearch.transport.InboundHandler.messageReceived(InboundHandler.java:118)
	    at org.elasticsearch.transport.InboundHandler.inboundMessage(InboundHandler.java:97)
	    at org.elasticsearch.transport.InboundHandlerTests.testLogsSlowInboundProcessing(InboundHandlerTests.java:315)
	    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	    at java.base/java.lang.reflect.Method.invoke(Method.java:568)

This doesn't actually cause the test to fail, as the test is not checking for correct processing, and a response is returned, albeit an error response. However, with the changes introduced by #93376, this exception does cause that test to fail, as it changes the error behaviour to just close the channel, which fails the test if the close happens before the 'slow response' message was logged.
server/src/test/java/org/elasticsearch/transport/InboundHandlerTests.java
private final TestThreadPool threadPool = new TestThreadPool(getClass().getName());
    private final TransportVersion version = TransportVersion.CURRENT;
    private TaskManager taskManager;
    private Transport.ResponseHandlers responseHandlers;
    private Transport.RequestHandlers requestHandlers;
    private InboundHandler handler;
    private FakeTcpChannel channel;
    @Before
    public void setUp() throws Exception {
        super.setUp();
        taskManager = new TaskManager(Settings.EMPTY, threadPool, Collections.emptySet());
        channel = new FakeTcpChannel(randomBoolean(), buildNewFakeTransportAddress().address(), buildNewFakeTransportAddress().address());
        NamedWriteableRegistry namedWriteableRegistry = new NamedWriteableRegistry(Collections.emptyList());
        final boolean ignoreDeserializationErrors = true; 
        TransportHandshaker handshaker = new TransportHandshaker(version, threadPool, (n, c, r, v) -> {}, ignoreDeserializationErrors);
        TransportKeepAlive keepAlive = new TransportKeepAlive(threadPool, TcpChannel::sendMessage);
        OutboundHandler outboundHandler = new OutboundHandler(
            "node",
            version,
            new StatsTracker(),