[CI] CoreWithSecurityClientYamlTestSuiteIT test {yaml=simulate.ingest/10_basic/Test mapping validation from templates} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-intake #9434 / part4
• elasticsearch-periodic #3974 / openjdk22_checkpart4_java-matrix

Reproduction Line:

./gradlew ":x-pack:qa:core-rest-tests-with-security:yamlRestTest" --tests "org.elasticsearch.xpack.security.CoreWithSecurityClientYamlTestSuiteIT" -Dtests.method="test {yaml=simulate.ingest/10_basic/Test mapping validation from templates}" -Dtests.seed=993ADF32FE7370BD -Dtests.locale=he-Hebr-IL -Dtests.timezone=Asia/Kolkata -Druntime.java=22

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Failure at [simulate.ingest/10_basic:281]: got unexpected warning header [
	299 Elasticsearch-8.16.0-6ddc163ee70a1c938654a641cbca6ae0e68c1fcc "index template [v2_template] has index patterns [v2_strict_nonexistent*] matching patterns from existing older templates [global] with patterns (global => [*]); this template [v2_template] will take precedence during new index creation"
]

Issue Reasons:

• [main] 2 failures in test test {yaml=simulate.ingest/10_basic/Test mapping validation from templates} (1.8% fail rate in 109 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 test {yaml=simulate.ingest/10_basic/Test mapping validation from templates} (1.8% fail rate in 109 executions)

Build Scans:

• elasticsearch-intake #9434 / part4
• elasticsearch-periodic #3974 / openjdk22_checkpart4_java-matrix

[elasticsearchmachine]

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