SpringBoot BatchProperties has an outdated reference to JPA

Since JpaBatchConfigurer.java was removed, BatchAutoConfiguration.getIsolationLevelForCreate() is the only method that determines the default value for spring.batch.jdbc.isolation-level-for-create.

BatchAutoConfiguration.getIsolationLevelForCreate() does not consider the use of JPA.

With this PR, it is expected that the following documents will be fixed as well.

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#application-properties.integration.spring.batch.jdbc.isolation-level-for-create

Comment From: snicoll

Thanks again, @benelog

With this PR, it is expected that the following documents will be fixed as well.

Yes, it is generated automatically from the description.