Update to Remoting without protocols.

core/src/main/java/jenkins/slaves/JnlpSlaveAgentProtocol.java

 package jenkins.slaves;
 
-import hudson.Extension;
-import hudson.ExtensionList;
-import hudson.model.Computer;
-import java.io.IOException;
-import java.net.Socket;
-import java.util.Collections;
-import java.util.logging.Logger;
-import javax.inject.Inject;
 import jenkins.AgentProtocol;
 import jenkins.security.HMACConfidentialKey;
-import org.jenkinsci.Symbol;
-import org.jenkinsci.remoting.engine.JnlpConnectionState;
-import org.jenkinsci.remoting.engine.JnlpProtocol1Handler;
 
 /**
  * {@link AgentProtocol} that accepts connection from agents.
@@ -42,20 +31,11 @@ import org.jenkinsci.remoting.engine.JnlpProtocol1Handler;
  * @author Kohsuke Kawaguchi
  * @since 1.467
  */
-public class JnlpSlaveAgentProtocol extends AgentProtocol {
+public class JnlpSlaveAgentProtocol {
     /**
      * This secret value is used as a seed for agents.
      */
     public static final HMACConfidentialKey SLAVE_SECRET =
             new HMACConfidentialKey(JnlpSlaveAgentProtocol.class, "secret");
 
-    @Override
-    public String getName() {
-        return null;
-    }
-
-    @Override
-    public void handle(Socket socket) throws IOException, InterruptedException {
-
-    }
 }

pom.xml

@@ -102,7 +102,7 @@ THE SOFTWARE.
     <maven-war-plugin.version>3.2.3</maven-war-plugin.version>
 
     <!-- Bundled Remoting version -->
-    <remoting.version>3.36</remoting.version>
+    <remoting.version>3.40</remoting.version>
     <!-- Minimum Remoting version, which is tested for API compatibility -->
     <remoting.minimum.supported.version>3.14</remoting.minimum.supported.version>