[CI] MixedClusterEsqlSpecIT test {string.LucenePushdownMultipleIndices SYNC} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #6948 / 8.13.4_bwc
• elasticsearch-periodic #6941 / 8.14.3_bwc
• elasticsearch-periodic #6941 / 8.13.4_bwc

Reproduction Line:

./gradlew ":x-pack:plugin:esql:qa:server:mixed-cluster:v8.13.4#javaRestTest" -Dtests.class="org.elasticsearch.xpack.esql.qa.mixed.MixedClusterEsqlSpecIT" -Dtests.method="test {string.LucenePushdownMultipleOr SYNC}" -Dtests.seed=1BA307CA600A8223 -Dtests.bwc=true -Dtests.locale=en-GU -Dtests.timezone=Australia/LHI -Druntime.java=24

Applicable branches:
8.x

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

org.elasticsearch.client.ResponseException: method [POST], host [http://[::1]:39741], URI [/_query?pretty=true&error_trace=true], status line [HTTP/1.1 400 Bad Request]
¿eerror¿jroot_cause�¿dtypeqparsing_exceptionfreasonx*line 2:25: token recognition error at: ':'kstack_tracey
<org.elasticsearch.xpack.esql.parser.ParsingException: line 2:25: token recognition error at: ':'
	at org.elasticsearch.xpack.esql.parser.EsqlParser$1.syntaxError(EsqlParser.java:109)
	at org.antlr.v4.runtime.ProxyErrorListener.syntaxError(ProxyErrorListener.java:41)
	at org.antlr.v4.runtime.Lexer.notifyListeners(Lexer.java:364)
	at org.antlr.v4.runtime.Lexer.nextToken(Lexer.java:144)
	at org.elasticsearch.xpack.esql.parser.EsqlParser$ParametrizedTokenSource.nextToken(EsqlParser.java:135)
	at org.antlr.v4.runtime.BufferedTokenStream.fetch(BufferedTokenStream.java:169)
	at org.antlr.v4.runtime.BufferedTokenStream.sync(BufferedTokenStream.java:152)
	at org.antlr.v4.runtime.BufferedTokenStream.consume(BufferedTokenS
[truncated]

Issue Reasons:

• [8.x] 2 consecutive failures in step 8.13.4_bwc
• [8.x] 3 failures in test test {string.LucenePushdownMultipleIndices SYNC} (3.1% fail rate in 98 executions)
• [8.x] 2 failures in step 8.13.4_bwc (100.0% fail rate in 2 executions)
• [8.x] 2 failures in pipeline elasticsearch-periodic (100.0% fail rate in 2 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)

[idegtiarenko]

Fixed by #124625