chore: Upgrading NullAway to 0.13.4 and error prone to 2.49.0 (#840)

Author: ehsavoie

pom.xml

@@ -70,8 +70,8 @@
         <slf4j.version>2.0.17</slf4j.version>
         <logback.version>1.5.18</logback.version>
         <version.testcontainers>1.21.4</version.testcontainers>
-        <error-prone.version>2.47.0</error-prone.version>
-        <nullaway.version>0.13.1</nullaway.version>
+        <error-prone.version>2.49.0</error-prone.version>
+        <nullaway.version>0.13.4</nullaway.version>
         <error-prone.flag>-XDaddTypeAnnotationsToSymbol=true</error-prone.flag>
         <nullaway.args>-Xplugin:ErrorProne -XepDisableAllChecks -Xep:NullAway:ERROR -Xep:RequireExplicitNullMarking:WARN -XepOpt:NullAway:ExhaustiveOverride=true -XepOpt:NullAway:OnlyNullMarked=true -XepOpt:NullAway:JSpecifyMode=true -XepExcludedPaths:.*/src/test/.* -XepDisableWarningsInGeneratedCode</nullaway.args>
 

server-common/src/main/java/org/a2aproject/sdk/server/events/MainEventBusProcessor.java

@@ -14,10 +14,8 @@
 import org.a2aproject.sdk.server.tasks.TaskSerializationException;
 import org.a2aproject.sdk.server.tasks.TaskStore;
 import org.a2aproject.sdk.spec.A2AError;
-import org.a2aproject.sdk.spec.A2AServerException;
 import org.a2aproject.sdk.spec.Event;
 import org.a2aproject.sdk.spec.InternalError;
-import org.a2aproject.sdk.spec.Message;
 import org.a2aproject.sdk.spec.Task;
 import org.a2aproject.sdk.spec.StreamingEventKind;
 import org.a2aproject.sdk.spec.TaskArtifactUpdateEvent;
@@ -134,6 +132,7 @@ public void setPushNotificationExecutor(java.util.concurrent.Executor executor)
         this.pushNotificationExecutor = executor;
     }
 
+    @SuppressWarnings("NullAway.Init")
     @PostConstruct
     void start() {
         processorThread = new Thread(this, "MainEventBusProcessor");

server-common/src/main/java/org/a2aproject/sdk/server/requesthandlers/DefaultRequestHandler.java

@@ -66,7 +66,6 @@
 import org.a2aproject.sdk.spec.TaskPushNotificationConfig;
 import org.a2aproject.sdk.spec.TaskQueryParams;
 import org.a2aproject.sdk.spec.TaskState;
-import org.a2aproject.sdk.spec.TaskStatusUpdateEvent;
 import org.a2aproject.sdk.spec.UnsupportedOperationError;
 import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
@@ -270,6 +269,7 @@ public DefaultRequestHandler(AgentExecutor agentExecutor, TaskStore taskStore,
         this.requestContextBuilder = () -> new SimpleRequestContextBuilder(taskStore, false);
     }
 
+    @SuppressWarnings("NullAway.Init")
     @PostConstruct
     void initConfig() {
         agentCompletionTimeoutSeconds = Integer.parseInt(