### Why are the changes needed?
This PR removes the page https://kyuubi.readthedocs.io/en/v1.10.1/client/python/pyspark.html and merges the most content into https://kyuubi.readthedocs.io/en/v1.10.1/extensions/engines/spark/jdbc-dialect.html, some original content of the latter is also modified.
The current docs are misleading, I got asked several times by users why they follow the [Kyuubi PySpark docs](https://kyuubi.readthedocs.io/en/v1.10.1/client/python/pyspark.html) to access data stored in Hive warehouse is too slow.
Actually, accessing HiveServer2/STS from Spark JDBC data source is discouraged by the Spark community, see [SPARK-47482](https://github.com/apache/spark/pull/45609), even though it's technical feasible.
### How was this patch tested?
It's a docs-only change, review is required.
### Was this patch authored or co-authored using generative AI tooling?
No.
Closes#7036 from pan3793/jdbc-ds-docs.
Closes#7036
c00ce0706 [Cheng Pan] style
f2676bd23 [Cheng Pan] [DOCS] Improve docs for kyuubi-extension-spark-jdbc-dialect
Authored-by: Cheng Pan <chengpan@apache.org>
Signed-off-by: Cheng Pan <chengpan@apache.org>
6da0e62baf