[CI] AdaptiveAllocationsScalerServiceTests test_scaleDownToZero_whenNoRequests failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic-platform-support #11314 / windows-2019_checkpart4_platform-support-windows
• elasticsearch-periodic-platform-support #11262 / windows-2019_checkpart4_platform-support-windows

Reproduction Line:

gradlew ":x-pack:plugin:ml:test" --tests "org.elasticsearch.xpack.ml.inference.adaptiveallocations.AdaptiveAllocationsScalerServiceTests.test_scaleDownToZero_whenNoRequests" -Dtests.seed=81687EF0CE1538A0 -Dtests.locale=kn-Knda-IN -Dtests.timezone=Canada/Atlantic -Druntime.java=25

Applicable branches:
8.19

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

org.mockito.exceptions.verification.TooFewActualInvocations: 
client.threadPool();
Wanted 2 times:
-> at org.elasticsearch.xpack.ml.inference.adaptiveallocations.AdaptiveAllocationsScalerServiceTests.test_scaleDownToZero_whenNoRequests(AdaptiveAllocationsScalerServiceTests.java:314)
But was 1 time:
-> at org.elasticsearch.xpack.core.ClientHelper.executeAsyncWithOrigin(ClientHelper.java:239)

Issue Reasons:

• [8.19] 2 failures in test test_scaleDownToZero_whenNoRequests (0.6% fail rate in 332 executions)
• [8.19] 2 failures in step windows-2019_checkpart4_platform-support-windows (18.2% fail rate in 11 executions)
• [8.19] 2 failures in pipeline elasticsearch-periodic-platform-support (18.2% fail rate in 11 executions)

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

[elasticsearchmachine]

Pinging @elastic/ml-core (Team:ML)