[CI] FrozenSearchableSnapshotsIntegTests testCreateAndRestorePartialSearchableSnapshot failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic-platform-support #5011 / almalinux-8-aarch64_checkpart2_platform-support-arm
• elasticsearch-periodic-platform-support #4926 / almalinux-8_platform-support-unix
• elasticsearch-periodic-platform-support #4921 / windows-2016_checkpart2_platform-support-windows

Reproduction Line:

./gradlew ":x-pack:plugin:searchable-snapshots:internalClusterTest" --tests "org.elasticsearch.xpack.searchablesnapshots.FrozenSearchableSnapshotsIntegTests.testCreateAndRestorePartialSearchableSnapshot" -Dtests.seed=9A385DEE6AB9979E -Dtests.locale=saq-KE -Dtests.timezone=America/Argentina/Tucuman -Druntime.java=23

Applicable branches:
8.x

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Translog should exist
Expected: is <true>
     but: was <false>

Issue Reasons:

• [8.x] 3 failures in test testCreateAndRestorePartialSearchableSnapshot (0.5% fail rate in 622 executions)
• [8.x] 3 failures in pipeline elasticsearch-periodic-platform-support (17.6% fail rate in 17 executions)

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

[elasticsearchmachine]

Pinging @elastic/es-distributed-indexing (Team:Distributed Indexing)

[ankikuma]

The test is complaining at the following line in 8.x:
assertBusy(() -> assertShardFolders(restoredIndexName, true), 30, TimeUnit.SECONDS);

This timeout was increased 2 years ago. See #84942

Some additional tracing was added here.

@tlrx can you take a look, I think you might have some more context for this.