Fix TimeSeriesRateAggregatorTests file leak

[cbuescher]

With Lucene 10, IndexWriter requires a parent document field in order to use index sorting with document blocks. In production code, we already use "setParentField" when creating an index writer configuration in InternalEngine, but some aggregation tests with nested docs still seem to use index writers without the parent field set. The IAE exception we get here now that Lucene 10 is merged hides another IAE that was tested for in TimeSeriesRateAggregatorTests#testNestedWithinAutoDateHistogram and on top of that occasionally leads to test failures due to file leaks as observed in #115238.

Closes #115238

[elasticsearchmachine]

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

[cbuescher]

@kkrik-es you seem to be familiar with the Lucene changes in this area, is my reasoning above correct?
The IAE we get without this change now satisfies expected exception class in the test in question but since its thrown earlier can lead to the IndexWriter not being closed properly, which occasionally gets detected by the test infra as a file leak.

[cbuescher]

@kkrik-es I saw you fixed the Leak issue with the change in #115345, however I believe that we are now throwing a different IAE than before the merge of Lucene 10 (in a different location), so I think this change here still applies. When the parent field is set we don't need to add documents separately and get back the "old" IAE from before the Lucene 10 update. Would you mind taking a look and let me know if my thinking here is right?

[cbuescher]

/cc @iverase

[kkrik-es]

I am really not familiar with these changes, just noticed that @iverase applied them elsewhere..

If Ignacio is fine with it and the following test passes, I've no objection:

./gradlew ":x-pack:plugin:analytics:test" --tests "org.elasticsearch.xpack.analytics.rate.TimeSeriesRateAggregatorTests" -Dtests.seed=509E2AFA17E6D235 -Dtests.locale=en -Dtests.timezone=Etc/UTC -Druntime.java=22

[cbuescher]

./gradlew ":x-pack:plugin:analytics:test" --tests "org.elasticsearch.xpack.analytics.rate.TimeSeriesRateAggregatorTests" -Dtests.seed=509E2AFA17E6D235 -Dtests.locale=en -Dtests.timezone=Etc/UTC -Druntime.java=22

That passes. I asked you because this change in InternalEngine that also sets the parent field was made by you. I think the change in the IAE that is being thrown went unnoticed because we don't check it message so far (which I added here)

[kkrik-es]

I asked you because this change in InternalEngine that also sets the parent field was made by you. I think the change in the IAE that is being thrown went unnoticed because we don't check it message so far (which I added here)

I see, so we were missing setting the parent doc so there was a mismatch in Lucene land that led to errors? At any rate, I've no objection here.

[cbuescher]

@elasticmachine elasticsearch-ci/part-2