[CI] MixedClusterEsqlSpecIT test {fork.ForkWithCommonPrefilter SYNC} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-intake #18601 / 9.0.0_bwc-snapshots
• elasticsearch-intake #18599 / 9.0.0_bwc-snapshots
• elasticsearch-pull-request #58611 / 9.0.0_bwc-snapshots
• elasticsearch-pull-request #58611 / 8.19.0_bwc-snapshots
• elasticsearch-intake #18597 / 9.0.0_bwc-snapshots
• elasticsearch-pull-request #58609 / 9.0.0_bwc-snapshots
• elasticsearch-intake #18595 / 9.0.0_bwc-snapshots
• elasticsearch-intake #18592 / 9.0.0_bwc-snapshots
• elasticsearch-pull-request #58606 / 8.19.0_bwc-snapshots
• elasticsearch-pull-request #58606 / 9.0.0_bwc-snapshots

Reproduction Line:

./gradlew ":x-pack:plugin:esql:qa:server:mixed-cluster:v9.0.0#javaRestTest" -Dtests.class="org.elasticsearch.xpack.esql.qa.mixed.MixedClusterEsqlSpecIT" -Dtests.method="test {fork.ForkWithCommonPrefilter SYNC}" -Dtests.seed=24A94A617A227BA0 -Dtests.bwc=true -Dtests.locale=fr-CG -Dtests.timezone=Europe/Copenhagen -Druntime.java=23

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

org.elasticsearch.client.ResponseException: method [POST], host [http://[::1]:36185], URI [/_query?format=cbor&pretty=true&error_trace=true], status line [HTTP/1.1 400 Bad Request]
¿eerror¿jroot_cause�¿dtypeqparsing_exceptionfreasonxíline 3:3: mismatched input 'FORK' expecting {'dissect', 'drop', 'enrich', 'eval', 'grok', 'keep', 'limit', 'mv_expand', 'rename', 'sort', 'stats', 'where', 'lookup', DEV_INLINESTATS, DEV_INSIST, DEV_LOOKUP, DEV_JOIN_LEFT, DEV_JOIN_RIGHT}kstack_tracey<org.elasticsearch.xpack.esql.parser.ParsingException: line 3:3: mismatched input 'FORK' expecting {'dissect', 'drop', 'enrich', 'eval', 'grok', 'keep', 'limit', 'mv_expand', 'rename', 'sort', 'stats', 'where', 'lookup', DEV_INLINESTATS, DEV_INSIST, DEV_LOOKUP, DEV_JOIN_LEFT, DEV_JOIN_RIGHT}
	at org.elasticsearch.xpack.esql.parser.EsqlParser$1.syntaxError(EsqlParser.java:149)
	at org.antlr.v4.runtime.ProxyErrorListener.syntaxError(ProxyErrorListener.java:41)
	at org.antlr.v4.runtime.Parser.notifyErrorListeners
[truncated]

Issue Reasons:

• [main] 11 failures in test test {fork.ForkWithCommonPrefilter SYNC} (34.4% fail rate in 32 executions)
• [main] 2 failures in step 8.19.0_bwc-snapshots (14.3% fail rate in 14 executions)
• [main] 9 failures in step 9.0.0_bwc-snapshots (50.0% fail rate in 18 executions)
• [main] 6 failures in pipeline elasticsearch-intake (46.2% fail rate in 13 executions)
• [main] 3 failures in pipeline elasticsearch-pull-request (60.0% fail rate in 5 executions)

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

[elasticsearchmachine]

This has been muted on branch main

Mute Reasons:

• [main] 2 consecutive failures in test test {fork.ForkWithCommonPrefilter SYNC}
• [main] 2 consecutive failures in step 9.0.0_bwc-snapshots
• [main] 7 failures in test test {fork.ForkWithCommonPrefilter SYNC} (43.8% fail rate in 16 executions)
• [main] 6 failures in step 9.0.0_bwc-snapshots (60.0% fail rate in 10 executions)
• [main] 4 failures in pipeline elasticsearch-intake (57.1% fail rate in 7 executions)
• [main] 2 failures in pipeline elasticsearch-pull-request (66.7% fail rate in 3 executions)

Build Scans:

• elasticsearch-intake #18597 / 9.0.0_bwc-snapshots
• elasticsearch-pull-request #58609 / 9.0.0_bwc-snapshots
• elasticsearch-intake #18595 / 9.0.0_bwc-snapshots
• elasticsearch-intake #18592 / 9.0.0_bwc-snapshots
• elasticsearch-pull-request #58606 / 8.19.0_bwc-snapshots
• elasticsearch-pull-request #58606 / 9.0.0_bwc-snapshots
• elasticsearch-intake #18590 / 9.0.0_bwc-snapshots

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)