[CI] MappingStatsTests testToXContent failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic-platform-support #11513 / rhel-10_platform-support-unix
• elasticsearch-periodic-platform-support #11506 / rhel-10_platform-support-unix
• elasticsearch-periodic-platform-support #11502 / rhel-10_platform-support-unix
• elasticsearch-periodic-platform-support #11492 / rhel-10_platform-support-unix
• elasticsearch-periodic-platform-support #11487 / rhel-10_platform-support-unix

Reproduction Line:

./gradlew ":server:test" --tests "org.elasticsearch.action.admin.cluster.stats.MappingStatsTests.testToXContent" -Dtests.seed=8D29E178FDEB4284 -Dtests.locale=dav-Latn-KE -Dtests.timezone=Africa/Tunis -Druntime.java=25

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

org.junit.ComparisonFailure: expected:<..._mapping_size" : "26[0b",
    "total_deduplicated_mapping_size_in_bytes" : 260],
    "field_types" ...> but was:<..._mapping_size" : "26[1b",
    "total_deduplicated_mapping_size_in_bytes" : 261],
    "field_types" ...>

Issue Reasons:

• [main] 5 consecutive failures in step rhel-10_platform-support-unix
• [main] 5 failures in test testToXContent (0.5% fail rate in 991 executions)
• [main] 5 failures in step rhel-10_platform-support-unix (100.0% fail rate in 5 executions)
• [main] 5 failures in pipeline elasticsearch-periodic-platform-support (100.0% 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-storage-engine (Team:StorageEngine)

[kkrik-es]

This only happens in rhel-10_platform-support-unix, and started right after #137640 . I wonder if this is due to jvm being different, @brianseeders fyi.