Update JPA samples to use the new chunk-oriented step implementation

Author: fmbenhassine

spring-batch-samples/src/main/java/org/springframework/batch/samples/jpa/JpaJobConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023 the original author or authors.
+ * Copyright 2023-2025 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.
@@ -70,8 +70,8 @@ public JpaItemWriter<CustomerCredit> itemWriter(EntityManagerFactory entityManag
 	public Job job(JobRepository jobRepository, JpaTransactionManager jpaTransactionManager,
 			JpaPagingItemReader<CustomerCredit> itemReader, JpaItemWriter<CustomerCredit> itemWriter) {
 		return new JobBuilder("ioSampleJob", jobRepository)
-			.start(new StepBuilder("step1", jobRepository)
-				.<CustomerCredit, CustomerCredit>chunk(2, jpaTransactionManager)
+			.start(new StepBuilder("step1", jobRepository).<CustomerCredit, CustomerCredit>chunk(2)
+				.transactionManager(jpaTransactionManager)
 				.reader(itemReader)
 				.processor(new CustomerCreditIncreaseProcessor())
 				.writer(itemWriter)

spring-batch-samples/src/main/java/org/springframework/batch/samples/jpa/JpaRepositoryJobConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023 the original author or authors.
+ * Copyright 2023-2025 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.
@@ -83,8 +83,8 @@ public RepositoryItemWriter<CustomerCredit> itemWriter(CustomerCreditCrudReposit
 	public Job job(JobRepository jobRepository, JpaTransactionManager jpaTransactionManager,
 			RepositoryItemReader<CustomerCredit> itemReader, RepositoryItemWriter<CustomerCredit> itemWriter) {
 		return new JobBuilder("ioSampleJob", jobRepository)
-			.start(new StepBuilder("step1", jobRepository)
-				.<CustomerCredit, CustomerCredit>chunk(2, jpaTransactionManager)
+			.start(new StepBuilder("step1", jobRepository).<CustomerCredit, CustomerCredit>chunk(2)
+				.transactionManager(jpaTransactionManager)
 				.reader(itemReader)
 				.processor(new CustomerCreditIncreaseProcessor())
 				.writer(itemWriter)