[CI] VectorSimilarityFunctionsIT testSimilarityBetweenVectors {functionName=v_cosine similarityFunction=COSINE} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #9566 / single-processor-node-tests
• elasticsearch-periodic-platform-support #9556 / rhel-8_platform-support-unix

Reproduction Line:

./gradlew ":x-pack:plugin:esql:internalClusterTest" --tests "org.elasticsearch.xpack.esql.vector.VectorSimilarityFunctionsIT.testSimilarityBetweenVectors {functionName=v_cosine similarityFunction=COSINE}" -Dtests.seed=700D55E9C2CCC2E4 -Dtests.configure_test_clusters_with_one_processor=true -Dtests.locale=bo-CN -Dtests.timezone=Brazil/Acre -Druntime.java=24

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Leftover exchanges ExchangeService{sinks=[t5WWBH4xRwqo_v0h6DBwGA:781/1]} on node node_s1

Issue Reasons:

• [main] 2 failures in test testSimilarityBetweenVectors {functionName=v_cosine similarityFunction=COSINE} (1.1% fail rate in 179 executions)

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

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)

[GalLalouche]

Probably same root cause as #131361.

[elasticsearchmachine]

Pinging @elastic/es-search-relevance (Team:Search Relevance)

[carlosdelest]

Closing as completed by #132288