[CI] ThreadPoolMergeExecutorServiceDiskSpaceTests testAbortingOrRunningMergeTaskHoldsUpBudget failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic-platform-support #9020 / rocky-9_platform-support-unix
• elasticsearch-periodic #8955 / openjdk17_checkpart1_java-fips-matrix
• elasticsearch-periodic-platform-support #8963 / rhel-7_platform-support-unix

Reproduction Line:

./gradlew ":server:test" --tests "org.elasticsearch.index.engine.ThreadPoolMergeExecutorServiceDiskSpaceTests.testAbortingOrRunningMergeTaskHoldsUpBudget" -Dtests.seed=21E167790644E370 -Dtests.locale=da-GL -Dtests.timezone=Atlantic/Jan_Mayen -Druntime.java=24

Applicable branches:
8.19

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

org.mockito.exceptions.verification.WantedButNotInvoked: 
Wanted but not invoked:
mergeTask.schedule();
-> at org.elasticsearch.index.engine.ThreadPoolMergeExecutorServiceDiskSpaceTests.lambda$testAbortingOrRunningMergeTaskHoldsUpBudget$22(ThreadPoolMergeExecutorServiceDiskSpaceTests.java:578)

However, there were exactly 201 interactions with this mock:
mergeTask.hasStartedRunning();
-> at org.elasticsearch.index.engine.ThreadPoolMergeExecutorService.submitMergeTask(ThreadPoolMergeExecutorService.java:241)

mergeTask.supportsIOThrottling();
-> at org.elasticsearch.index.engine.ThreadPoolMergeExecutorService.submitMergeTask(ThreadPoolMergeExecutorService.java:248)

mergeTask.estimatedRemainingMergeSize();
-> at org.elasticsearch.index.engine.ThreadPoolMergeExecutorService$PriorityBlockingQueueWithBudget.enqueue(ThreadPoolMergeExecutorService.java:597)

mergeTask.estimatedRemainingMergeSize();
-> at org.elasticsearch.index.engine.ThreadPoolMergeExecutorService$PriorityBlockingQueueWithB
[truncated]

Issue Reasons:

• [8.19] 3 failures in test testAbortingOrRunningMergeTaskHoldsUpBudget (0.8% fail rate in 357 executions)
• [8.19] 2 failures in pipeline elasticsearch-periodic-platform-support (22.2% fail rate in 9 executions)

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

[elasticsearchmachine]

Pinging @elastic/es-distributed-indexing (Team:Distributed Indexing)

[albertzaharovits]

The test is now unmuted and hopefully #130430 fixes it (but probably won't).
I'll take a look again at failures that include #130430.