[CI] ClientYamlTestSuiteIT test {yaml=indices.simulate_index_template/10_basic/Simulate index template with data stream with mapping and setting overrides} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #9965 / release-tests
• elasticsearch-pull-request #85213 / checkpart1_release-tests
• elasticsearch-periodic #9958 / release-tests
• elasticsearch-periodic #9951 / release-tests

Reproduction Line:

./gradlew ":rest-api-spec:yamlRestTest" --tests "org.elasticsearch.test.rest.ClientYamlTestSuiteIT" -Dtests.method="test {yaml=indices.simulate_index_template/10_basic/Simulate index template with data stream with mapping and setting overrides}" -Dtests.seed=1DE7951F3BF6C6AA -Dbuild.snapshot=false -Dtests.jvm.argline="-Dbuild.snapshot=false" -Dlicense.key=x-pack/license-tools/src/test/resources/public.key -Dtests.locale=id -Dtests.timezone=Africa/Cairo -Druntime.java=24

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Failure at [indices.simulate_index_template/10_basic:279]: expected [2xx] status code but api [indices.put_data_stream_mappings] returned [400 Bad Request] [{"error":"no handler found for uri [/_data_stream/test/_mappings?error_trace=true] and method [PUT]"}]

Issue Reasons:

• [main] 3 consecutive failures in step release-tests
• [main] 4 failures in test test {yaml=indices.simulate_index_template/10_basic/Simulate index template with data stream with mapping and setting overrides} (3.7% fail rate in 107 executions)
• [main] 3 failures in step release-tests (100.0% fail rate in 3 executions)
• [main] 3 failures in pipeline elasticsearch-periodic (100.0% fail rate in 3 executions)

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

[elasticsearchmachine]

Pinging @elastic/es-storage-engine (Team:StorageEngine)

[gmarouli]

Added in #132131 , looks like the new API is not "visible" here. Assigning it to @masseyke .

So cool to see data streams having their own settings & mappings :)

[elasticsearchmachine]

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