## What changes were proposed in this pull request?
In PR https://github.com/apache/spark/pull/24365, we pass in the partitionBy columns as options in `DataFrameWriter`. To make this change less intrusive for a patch release, we added a feature flag `LEGACY_PASS_PARTITION_BY_AS_OPTIONS` with the default to be false.
For 3.0, we should just do the correct behavior for DSV1, i.e., always passing partitionBy as options, and remove this legacy feature flag.
## How was this patch tested?
Existing tests.
Closes#24784 from liwensun/SPARK-27453-default.
Authored-by: liwensun <liwen.sun@databricks.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
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