[CI] DynamicMappingIT testDenseVectorDynamicMapping failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic-platform-support #8946 / almalinux-8_platform-support-unix
• elasticsearch-pull-request #77136 / part-1

Reproduction Line:

./gradlew ":server:internalClusterTest" --tests "org.elasticsearch.index.mapper.DynamicMappingIT.testDenseVectorDynamicMapping" -Dtests.seed=EA60295F92FBDEDF -Dtests.locale=th-TH-u-nu-thai-x-lvariant-TH -Dtests.timezone=Europe/Jersey -Druntime.java=24

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: null

Issue Reasons:

• [main] 2 failures in test testDenseVectorDynamicMapping (12.5% fail rate in 16 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 main

Mute Reasons:

• [main] 2 failures in test testDenseVectorDynamicMapping (12.5% fail rate in 16 executions)

Build Scans:

• elasticsearch-periodic-platform-support #8946 / almalinux-8_platform-support-unix
• elasticsearch-pull-request #77136 / part-1

[elasticsearchmachine]

Pinging @elastic/es-search-foundations (Team:Search Foundations)

[pmpailis]

I was able to reproduce it locally when using stress-ng to starve it from resources. Seems like we try to check for mappings, before the mapping change from the second document that was indexed actually propagates to master. Will open a PR to make use of assertBusy as with test cases in the same class.