* Revert "[ML] Export ML model as sklearn Pipeline (#509)"
This reverts commit 0576114a1d886eafabca3191743a9bea9dc20b1a.
* Keep useful changes
* formatting
* Remove obsolete test matrix configuration and update version references in documentation and Noxfile
* formatting
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Co-authored-by: Quentin Pradet <quentin.pradet@elastic.co>