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
import org.elasticsearch.common.bytes.BytesReference;
import org.elasticsearch.common.bytes.ReleasableBytesReference;
import org.elasticsearch.common.io.stream.InputStreamStreamInput;
import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
import org.elasticsearch.common.io.stream.RecyclerBytesStreamOutput;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.logging.Loggers;
import org.elasticsearch.common.network.HandlingTimeTracker;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.util.PageCacheRecycler;
import org.elasticsearch.core.TimeValue;
import org.elasticsearch.core.Tuple;
import org.elasticsearch.tasks.TaskManager;
import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.test.MockLogAppender;
import org.elasticsearch.test.TransportVersionUtils;
import org.elasticsearch.threadpool.TestThreadPool;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.tracing.Tracer;
import org.junit.After;
import org.junit.Before;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import static org.hamcrest.Matchers.instanceOf;
public class InboundHandlerTests extends ESTestCase {