[CI] FileSettingsServiceTests testInvalidJSON failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-intake #12657 / part1
• elasticsearch-pull-request #40341 / part-1

Reproduction Line:

./gradlew ":server:test" --tests "org.elasticsearch.reservedstate.service.FileSettingsServiceTests.testInvalidJSON" -Dtests.seed=AC5A8B07FA7E8BF2 -Dtests.locale=sbp-TZ -Dtests.timezone=Etc/GMT+5 -Druntime.java=23

Applicable branches: main

Reproduces locally?: N/A

Failure History: See dashboard&_a=(controlGroupState:(initialChildControlState:('0c0c9cb8-ccd2-45c6-9b13-96bac4abc542':(dataViewId:fbbdc689-be23-4b3d-8057-aa402e9ed0c5,fieldName:task.keyword,order:0,selectedOptions:!(),title:'GradleTask',type:optionsListControl),'4e6ad9d6-6fdc-4fcc-bf1a-aa6ca79e0850':(dataViewId:fbbdc689-be23-4b3d-8057-aa402e9ed0c5,fieldName:className.keyword,order:1,selectedOptions:!(org.elasticsearch.reservedstate.service.FileSettingsServiceTests),title:'Suite',type:optionsListControl),'144933da-5c1b-4257-a969-7f43455a7901':(dataViewId:fbbdc689-be23-4b3d-8057-aa402e9ed0c5,fieldName:name.keyword,order:2,selectedOptions:!(testInvalidJSON),title:'Test',type:optionsListControl)))))

Failure Message:

org.mockito.exceptions.verification.WantedButNotInvoked: 
Wanted but not invoked:
fileSettingsService.onProcessFileChangesException(
    <custom argument matcher>
);
-> at org.elasticsearch.reservedstate.service.FileSettingsServiceTests.testInvalidJSON(FileSettingsServiceTests.java:317)

However, there were exactly 3 interactions with this mock:
fileSettingsService.doStart();
-> at org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:51)

fileSettingsService.processFileOnServiceStart();
-> at org.elasticsearch.common.file.AbstractFileWatchingService.processSettingsOnServiceStartAndNotifyListeners(AbstractFileWatchingService.java:304)

fileSettingsService.processFileChanges();
-> at org.elasticsearch.common.file.AbstractFileWatchingService.processSettingsAndNotifyListeners(AbstractFileWatchingService.java:316)

Issue Reasons:

• [main] 2 failures in test testInvalidJSON (40.0% fail rate in 5 executions)

Note: This issue was created using new test triage automation. Please report issues or feedback to es-delivery.

[elasticsearchmachine]

This has been muted on branch main

Mute Reasons:

• [main] 2 failures in test testInvalidJSON (40.0% fail rate in 5 executions)

Build Scans:

• elasticsearch-intake #12657 / part1
• elasticsearch-pull-request #40341 / part-1

[elasticsearchmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)