[CI] CrossClustersCancellationIT testCancel failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic-platform-support #8786 / oraclelinux-8_platform-support-unix
• elasticsearch-periodic #8735 / graalvm-ce17_checkpart3_java-matrix
• elasticsearch-periodic #8729 / openjdk17_checkpart3_java-matrix

Reproduction Line:

./gradlew ":x-pack:plugin:esql:internalClusterTest" --tests "org.elasticsearch.xpack.esql.action.CrossClustersCancellationIT.testCancel" -Dtests.seed=54C10C195B2BACD7 -Dtests.locale=pcm -Dtests.timezone=Australia/West -Druntime.java=23

Applicable branches:
8.17

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: 
Expected: a string containing "proxy timeout"
     but: was "cancelled on failure"

Issue Reasons:

• [8.17] 3 failures in test testCancel (1.4% fail rate in 222 executions)
• [8.17] 2 failures in pipeline elasticsearch-periodic (25.0% fail rate in 8 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)