IntelliJ HOCON plugin: tests failing after upgrading to 2024.2 EAP

Hi, I'm trying to upgrade the HOCON plugin (https://github.com/AVSystem/intellij-hocon) to IDEA 2024.2.

I have a bunch of tests extending FileSetTestCase. After upgrading to IJ 2024.2 EAP, they started failing with a very enigmatic exception:

[error] Test com.intellij.FileSetTestCase$ActualTest.unquotedToEmpty.test failed: com.intellij.platform.instanceContainer.InstanceNotRegisteredException: com.intellij.platform.settings.SettingsController, took 0.949 sec
[error]     at com.intellij.platform.instanceContainer.internal.InstanceContainerImpl.instance(InstanceContainerImpl.kt:66)
[error]     at com.intellij.serviceContainer.ComponentManagerImpl.getServiceAsync(ComponentManagerImpl.kt:691)
[error]     at com.intellij.platform.ide.bootstrap.ApplicationLoader$initConfigurationStore$2$1.invokeSuspend(ApplicationLoader.kt:576)
[error]     at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
[error]     at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:104)
[error]     at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:608)
[error]     at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:873)
[error]     at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:763)
[error]     at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:750)

More details: https://github.com/AVSystem/intellij-hocon/actions/runs/9444594134/job/26010468665?pr=48

Example failing test: https://github.com/AVSystem/intellij-hocon/blob/idea242/test/org/jetbrains/plugins/hocon/parser/HoconParserTest.scala

This failure is extremely opaque to me, and it's happening inside async code, so I don't even have a meaningful stack trace. Can you help me with this?