UnboundIdContainer fails with TestContext

[rwinch]

This appears to be related to

• spring-projects/spring-framework@dbe89ab
• Introduce ConfigurableApplicationContext.restart() method spring-framework#35171
• Pause unused application contexts in the TestContext framework spring-framework#35168

Adding @DirtiesContext works around the issue

Note that part of the problem is a little challenging when using an ephemeral port. We cannot just start and restart the context because:

1. If we allocate a new port then Beans that used the previous port information will be stale
2. If we preserve the same port, the port may have been taken in the meantime

I spoke to @jhoeller and @sbrannen offline and it was suggested that we might be able to do something like this:

public void stop() {
    if (port == 0 && context != null && !context.isClosed()) return;
}