Stop using deprecated StepExecutionListenerSupport in document

Signed-off-by: Yanming Zhou <zhouyanming@gmail.com>

Author: quaff

spring-batch-docs/modules/ROOT/pages/common-patterns.adoc

@@ -686,7 +686,7 @@ the class definition for `NoWorkFoundStepExecutionListener`:
 
 [source, java]
 ----
-public class NoWorkFoundStepExecutionListener extends StepExecutionListenerSupport {
+public class NoWorkFoundStepExecutionListener implements StepExecutionListener {
 
     public ExitStatus afterStep(StepExecution stepExecution) {
         if (stepExecution.getReadCount() == 0) {

spring-batch-docs/modules/ROOT/pages/testing.adoc

@@ -303,7 +303,7 @@ the following code snippet shows:
 
 [source, java]
 ----
-public class NoWorkFoundStepExecutionListener extends StepExecutionListenerSupport {
+public class NoWorkFoundStepExecutionListener implements StepExecutionListener {
 
     public ExitStatus afterStep(StepExecution stepExecution) {
         if (stepExecution.getReadCount() == 0) {