[CI] MixedClusterEsqlSpecIT test {where-like.RlikeWithUpperTurnedInsensitive SYNC} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #8611 / 8.11.4_bwc
• elasticsearch-periodic #8604 / 8.11.4_bwc
• elasticsearch-periodic #8592 / 8.11.4_bwc
• elasticsearch-periodic #8585 / 8.11.4_bwc

Reproduction Line:

./gradlew ":x-pack:plugin:esql:qa:server:mixed-cluster:v8.11.4#javaRestTest" -Dtests.class="org.elasticsearch.xpack.esql.qa.mixed.MixedClusterEsqlSpecIT" -Dtests.method="test {where-like.LikeWithLowerTurnedInsensitiveNotPushedDown SYNC}" -Dtests.seed=17444B102F35E426 -Dtests.bwc=true -Dtests.locale=bs-Cyrl-BA -Dtests.timezone=Africa/Niamey -Druntime.java=24

Applicable branches:
8.19

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

org.elasticsearch.client.ResponseException: method [POST], host [http://[::1]:41775], URI [/_query?pretty=true&error_trace=true], status line [HTTP/1.1 400 Bad Request]
Warnings: [No limit defined, adding default limit of [500]]
:)
�ú�errorú�root_causeøú�typeUverification_exception�reasonàFound 1 problem
line 4:9: Unknown function [TO_LOWER], did you mean any of [to_long, to_ver, to_boolean, to_bool, to_integer, to_str, to_ulong]?ü�stack_traceäorg.elasticsearch.xpack.esql.analysis.VerificationException: Found 1 problem
line 4:9: Unknown function [TO_LOWER], did you mean any of [to_long, to_ver, to_boolean, to_bool, to_integer, to_str, to_ulong]?
	at org.elasticsearch.xpack.esql.analysis.Analyzer.verify(Analyzer.java:113)
	at org.elasticsearch.xpack.esql.analysis.Analyzer.analyze(Analyzer.java:107)
	at org.elasticsearch.xpack.esql.session.EsqlSession.lambda$analyzedPlan$2(EsqlSession.java:143)
	at org.elasticsearch.xpack.esql.session.EsqlSession.lambda$preAnalyze$5(EsqlSession.java:168)
[truncated]

Issue Reasons:

• [8.19] 2 consecutive failures in step 8.11.4_bwc
• [8.19] 4 failures in test test {where-like.RlikeWithUpperTurnedInsensitive SYNC} (2.3% fail rate in 173 executions)
• [8.19] 4 failures in step 8.11.4_bwc (80.0% fail rate in 5 executions)
• [8.19] 4 failures in pipeline elasticsearch-periodic (80.0% fail rate in 5 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)

[fang-xing-esql]

This is a duplicate of #129018.

[dnhatn]

Fixed in #128979