Explicitly close ApplicationContexts and clean up warnings in tests

This commit also ensures that various test methods actually test
something now.

spring-web/src/test/java/org/springframework/remoting/caucho/CauchoRemotingTests.java

@@ -37,6 +37,7 @@ import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException
  * @author Sam Brannen
  * @since 16.05.2003
  */
+@SuppressWarnings("deprecation")
 public class CauchoRemotingTests {
 
 	@Test

spring-web/src/test/java/org/springframework/remoting/httpinvoker/HttpComponentsHttpInvokerRequestExecutorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -34,6 +34,7 @@ import static org.mockito.Mockito.withSettings;
 /**
  * @author Stephane Nicoll
  */
+@SuppressWarnings("deprecation")
 public class HttpComponentsHttpInvokerRequestExecutorTests {
 
 	@Test

spring-web/src/test/java/org/springframework/web/context/request/async/WebAsyncManagerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -381,6 +381,7 @@ public class WebAsyncManagerTests {
 	private static class SyncTaskExecutor extends SimpleAsyncTaskExecutor {
 
 		@Override
+		@SuppressWarnings("deprecation")
 		public void execute(Runnable task, long startTimeout) {
 			task.run();
 		}