Evaluate removal of RDD caching for MEMORY_ONLY in the Spark Dataset runner

[mosche]

A small simplification ... removing RDD caching for the Spark Dataset runner.

With the recent RDD linage fix (#25187) there's no visible improvement that justifies the added complexity. Moreover, the recommended storage level with Spark Datasets is MEMORY_AND_DISK (rather than MEMORY_ONLY). This makes RDD caching fairly irrelevant for production use cases with the Dataset runner.

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[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Nexmark Tests

[mosche]

Run Spark Runner Nexmark Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Java PreCommit

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark Runner Tpcds Tests

[mosche]

Run Spark StructuredStreaming ValidatesRunner

[mosche]

R: @echauchot
R: @aromanenko-dev

[github-actions]

Stopping reviewer notifications for this pull request: review requested by someone other than the bot, ceding control

[echauchot]

@mosche need to finish something, I'll take a look tomorrow or wednesday

[echauchot]

 @mosche reviewing ...

[echauchot]

Thanks Moritz ! Merging