SpringBoot Fix Javadoc in JobLauncherApplicationRunner

The JobLauncherApplicationRunner does not launch multiple jobs by the commit - https://github.com/spring-projects/spring-boot/commit/55d6a87fefcd1f258a0ca5bc104b82b3bebf8aa1 . The Javadoc in JobLauncherApplicationRunner was not updated. This PR fixed it.

Comment From: benelog

The test in JettyServletWebServerFactoryTests failed.

https://ci.spring.io/teams/spring-boot/pipelines/spring-boot-3.1.x/jobs/build-pull-requests/builds/70#L63de80fd:5177

:spring-boot-project:spring-boot:test
    org.springframework.boot.web.embedded.jetty.JettyServletWebServerFactoryTests > whenServerIsShuttingDownGracefullyThenResponseToRequestOnIdleConnectionWillHaveAConnectionCloseHeader()

I guess my change didn't affect the failure.

Comment From: wilkinsona

@benelog Yeah, unfortunately that test is rather flaky. Don't worry about it.

Comment From: wilkinsona

@benelog Thank you very much, and congratulations on making your first contribution to Spring Boot.