[CI] XpackWithMultipleProjectsClientYamlTestSuiteIT class failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic-platform-support #7883 / oraclelinux-8_platform-support-unix
• elasticsearch-periodic-platform-support #7877 / rocky-8_platform-support-unix
• elasticsearch-periodic #7849 / encryption-at-rest
• elasticsearch-periodic #7849 / concurrent-search-tests
• elasticsearch-periodic-platform-support #7871 / almalinux-8_platform-support-unix
• elasticsearch-periodic #7843 / encryption-at-rest
• elasticsearch-periodic #7843 / concurrent-search-tests
• elasticsearch-periodic-platform-support #7859 / rhel-8_platform-support-unix
• elasticsearch-periodic #7837 / single-processor-node-tests
• elasticsearch-periodic #7837 / concurrent-search-tests

Reproduction Line:

undefined

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

undefined

Issue Reasons:

• [main] 19 failures in class org.elasticsearch.multiproject.test.XpackWithMultipleProjectsClientYamlTestSuiteIT (3.3% fail rate in 568 executions)
• [main] 4 failures in step part-2 (1.7% fail rate in 231 executions)
• [main] 2 failures in step encryption-at-rest (22.2% fail rate in 9 executions)
• [main] 2 failures in step single-processor-node-tests (33.3% fail rate in 6 executions)
• [main] 4 failures in step concurrent-search-tests (44.4% fail rate in 9 executions)
• [main] 2 failures in step almalinux-8_platform-support-unix (22.2% fail rate in 9 executions)
• [main] 2 failures in step rhel-8_platform-support-unix (25.0% fail rate in 8 executions)
• [main] 2 failures in step rocky-8_platform-support-unix (28.6% fail rate in 7 executions)
• [main] 6 failures in pipeline elasticsearch-periodic-platform-support (60.0% fail rate in 10 executions)
• [main] 5 failures in pipeline elasticsearch-periodic (50.0% fail rate in 10 executions)
• [main] 4 failures in pipeline elasticsearch-pull-request (1.7% fail rate in 231 executions)

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

[elasticsearchmachine]

Pinging @elastic/es-data-management (Team:Data Management)

[nielsbauman]

All these test failures seemed to have been caused by timeouts. My hunch is that this was caused by Make IndexTemplateRegistry project-aware #126986, which was merged a few days ago, around the same time the average runtime of this test suite significantly increases: https://es-delivery-stats.elastic.dev/app/r/s/BnqIq