[CI] XPackRestIT test {p0=esql/60_usage/Basic ESQL usage output (telemetry) non-snapshot version} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #4836 / release-tests
• elasticsearch-periodic #4826 / release-tests
• elasticsearch-periodic #4821 / release-tests
• elasticsearch-periodic #4816 / release-tests
• elasticsearch-periodic #4811 / release-tests
• elasticsearch-periodic #4806 / release-tests
• elasticsearch-periodic #4801 / release-tests
• elasticsearch-periodic #4796 / release-tests
• elasticsearch-periodic #4791 / release-tests
• elasticsearch-periodic #4786 / release-tests

Reproduction Line:

./gradlew ":x-pack:plugin:yamlRestTest" --tests "org.elasticsearch.xpack.test.rest.XPackRestIT.test {p0=esql/60_usage/Basic ESQL usage output (telemetry) non-snapshot version}" -Dtests.seed=C9CE1C02CF1BEA14 -Dbuild.snapshot=false -Dtests.jvm.argline="-Dbuild.snapshot=false" -Dlicense.key=x-pack/license-tools/src/test/resources/public.key -Dtests.locale=ksb-Latn-TZ -Dtests.timezone=Australia/Tasmania -Druntime.java=23

Applicable branches:
8.x

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Failure at [esql/60_usage:165]: field [esql.functions] doesn't have length [118]
Expected: <118>
     but: was <116>

Issue Reasons:

• [8.x] 14 consecutive failures in pipeline elasticsearch-periodic
• [8.x] 14 failures in test test {p0=esql/60_usage/Basic ESQL usage output (telemetry) non-snapshot version} (87.5% fail rate in 16 executions)
• [8.x] 14 failures in step release-tests (87.5% fail rate in 16 executions)
• [8.x] 14 failures in pipeline elasticsearch-periodic (100.0% fail rate in 14 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)

[luigidellaquila]

Need to manually backport #116470 (for some reason, auto-backport label didn't work)

[luigidellaquila]

Closed by #116580