Add missing deprecation note

This should have been part of 1ff04d53

Issue #2218

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/xml/StepParserStepFactoryBean.java

@@ -997,7 +997,10 @@ public class StepParserStepFactoryBean<I, O> implements FactoryBean<Step>, BeanN
 	 * concurrent processing to prevent thread pools from being overwhelmed. Defaults to
 	 * {@link TaskExecutorRepeatTemplate#DEFAULT_THROTTLE_LIMIT}.
 	 * @param throttleLimit The throttle limit to set.
+	 * @deprecated since 5.0, scheduled for removal in 6.0. This API is not intended for
+	 * end users anyway. It is only used by the XML namespace parser.
 	 */
+	@Deprecated(since = "5.0", forRemoval = true)
 	public void setThrottleLimit(Integer throttleLimit) {
 		this.throttleLimit = throttleLimit;
 	}

spring-batch-core/src/main/java/org/springframework/batch/core/step/factory/SimpleStepFactoryBean.java

@@ -446,7 +446,11 @@ public class SimpleStepFactoryBean<T, S> implements FactoryBean<Step>, BeanNameA
 	 * concurrent processing to prevent thread pools from being overwhelmed. Defaults to
 	 * {@link TaskExecutorRepeatTemplate#DEFAULT_THROTTLE_LIMIT}.
 	 * @param throttleLimit the throttle limit to set.
+	 * @deprecated since 5.0, scheduled for removal in 6.0. Use a pooled
+	 * {@link TaskExecutor} implementation with a limited capacity of its task queue
+	 * instead.
 	 */
+	@Deprecated(since = "5.0", forRemoval = true)
 	public void setThrottleLimit(int throttleLimit) {
 		this.throttleLimit = throttleLimit;
 	}

spring-batch-core/src/main/resources/org/springframework/batch/core/configuration/xml/spring-batch.xsd

@@ -684,7 +684,8 @@
 				<xsd:documentation><![CDATA[
 				This limits the number of tasks queued for concurrent
 				processing to prevent thread pools from being overwhelmed.
-				Default is 4.
+				Default is 4. This is deprecated in favor of using similar
+				features in TaskExecutor implementations.
 				]]></xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>