[CI] ReindexDatastreamIndexTransportActionIT testFailIfMetadataBlockSet failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-intake #17311 / part2
• elasticsearch-periodic-platform-support #6194 / almalinux-8_platform-support-unix

Reproduction Line:

./gradlew ":x-pack:plugin:migrate:internalClusterTest" --tests "org.elasticsearch.xpack.migrate.action.ReindexDatastreamIndexTransportActionIT.testTimestamp0AddedIfMissing" -Dtests.seed=AEBEE7CAD70EFEA8 -Dtests.locale=fy-NL -Dtests.timezone=Canada/Newfoundland -Druntime.java=23

Applicable branches:
8.18

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: All incoming requests on node [node_s3] should have finished. Expected 0 bytes for requests in-flight but got 298 bytes; pending tasks [[]]

Issue Reasons:

• [8.18] 2 failures in test testFailIfMetadataBlockSet (1.5% fail rate in 131 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 8.18

Mute Reasons:

• [8.18] 2 failures in test testFailIfMetadataBlockSet (1.5% fail rate in 131 executions)

Build Scans:

• elasticsearch-intake #17311 / part2
• elasticsearch-periodic-platform-support #6194 / almalinux-8_platform-support-unix

[elasticsearchmachine]

Pinging @elastic/es-data-management (Team:Data Management)

[parkertimmins]

Fixed by #121782