[BUG] org.opensearch.recovery.RelocationIT.testIndexSearchAndRelocateConcurrently is Flaky

[harishbhakuni]

Describe the bug

org.opensearch.recovery.RelocationIT.testIndexSearchAndRelocateConcurrently test is flaky.
Failed with following error in https://build.ci.opensearch.org/job/gradle-check/34934/:

java.lang.RuntimeException: Can't get cluster-manager node null

Related component

Other

To Reproduce

REPRODUCE WITH: ./gradlew ':server:internalClusterTest' --tests "org.opensearch.recovery.RelocationIT" -Dtests.seed=1331E65F9D8C26DF -Dtests.security.manager=true -Dtests.jvm.argline="-XX:TieredStopAtLevel=1 -XX:ReservedCodeCacheSize=64m" -Dtests.locale=en -Dtests.timezone=Etc/UTC -Druntime.java=21

However was not able to reproduce it locally with same seed.

Expected behavior

test should always pass.

Additional Details

Plugins
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Screenshots
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Host/Environment (please complete the following information):

• OS: [e.g. iOS]
• Version [e.g. 22]

Additional context
Another failing test from same suite: org.opensearch.recovery.RelocationIT.testRelocationWhileIndexingRandom {p0={"cluster.indices.replication.strategy":"SEGMENT"}}

[harishbhakuni]

Another failing test from same suite: org.opensearch.recovery.RelocationIT.testRelocationWhileIndexingRandom {p0={"cluster.indices.replication.strategy":"SEGMENT"}}

[andrross]

[Triage - attendees 1 2 3 4 5 6]
@harishbhakuni Thanks for filing.

[shwetathareja]

Failed again here - #14095 (comment)

[reta]

Closing in favour of #14309