[MINOR][CH] Remove residual Spark 3.2 branches from clickhouse tests

[LuciferYang]

What changes were proposed in this pull request?

Spark 3.2 was dropped by #11351 / #11687 / #11731 / #11887; the spark32 protected def in GlutenClickHouseWholeStageTransformerSuite was defined as sparkVersion.equals("3.2") and has been dead since. This PR removes the definition and prunes every reachable if (spark32) ... / if (!spark32) ... / ${if (spark32) ... else ...} branch to keep only the Spark 3.3+ path.

Test-code changes (all in backends-clickhouse/src/test/):

• GlutenClickHouseWholeStageTransformerSuite.scala: drop the protected def spark32 definition (always false).
• GlutenClickHouseTPCHBucketSuite.scala: hasSortByCol = !spark32 collapses to true on all supported Sparks; version-gated if (spark32) ... branches removed.
• GlutenClickHouseTPCHParquetBucketSuite.scala, GlutenClickHouseDeltaParquetWriteSuite.scala, GlutenClickHouseMergeTreeWriteSuite.scala, GlutenClickHouseMergeTreeOptimizeSuite.scala, GlutenClickHouseMergeTreeWriteOnHDFSSuite.scala, GlutenClickHouseMergeTreeWriteOnHDFSWithRocksDBMetaSuite.scala, GlutenClickHouseMergeTreeWriteOnS3Suite.scala, GlutenClickHouseMergeTreePathBasedWriteSuite.scala: every reachable if (spark32) ... else ... block, if (!spark32) ... guard, and inline ${if (spark32) "" else "SORTED BY (...)"} interpolation is reduced to the Spark 3.3+ path (always emit SORTED BY).
• GlutenClickHouseTPCDSParquetAQESuite.scala, GlutenClickHouseTPCDSParquetColumnarShuffleAQESuite.scala: comments narrowed from "On Spark 3.2, ... on Spark 3.3, ..." to describe only the surviving Spark 3.3+ shape.
• hive/GlutenClickHouseNativeWriteTableSuite.scala: drop stale // spark 3.2 without orc or parquet suffix comment.

Main-code change (one file):

• RowToCHNativeColumnarExec.scala: drop the // For spark 3.2. comment above withNewChildInternal. The override is required by TreeNode's API on every Spark version currently supported by Gluten, not a Spark 3.2-only quirk. Mirrors the same cleanup for RowToVeloxColumnarExec included in [MINOR] Align supported Spark version references #12525.

Explicitly kept for a separate follow-up PR (real refactor, not comment fix):

• backends-clickhouse/.../ExtendedColumnPruning.scala:66-72 — the local getAttributeToExtractValues re-implementation exists because Spark 3.2's upstream signature was 2-arg. On 3.3+ it is 3-arg; the local copy could be replaced with a delegate.
• backends-clickhouse/.../CHColumnarWrite.scala:157 — the bucketSpec reflection was needed for Spark 3.2, may be replaceable with direct access on 3.3+.
• CustomSum.scala:28 — historical provenance of a copied file, not a version gate; keep as-is.

How was this patch tested?

• mvn -pl backends-clickhouse -am install -Pspark-3.3,backends-clickhouse,delta: SUCCESS
• mvn -pl backends-clickhouse scalastyle:check spotless:check -Pspark-3.3,backends-clickhouse,delta: SUCCESS
• The pruned branches were dead code on every currently supported Spark profile, so runtime behavior is unchanged.

[github-actions]

Run Gluten Clickhouse CI on x86

[Copilot]

Pull request overview

This PR removes dead Spark 3.2-specific branches from the ClickHouse backend test suites (and one stale Spark 3.2-only comment in main code), simplifying tests now that Gluten supports Spark 3.3+ only.

Changes:

• Removed the spark32 version flag from ClickHouse whole-stage test base and pruned all reachable spark32/!spark32 branches in ClickHouse tests to the Spark 3.3+ path.
• Simplified ClickHouse MergeTree/Delta/TPCH/TPCDS test assertions and SQL DDL string generation (e.g., always emitting SORTED BY, always expecting the Spark 3.3+ plan shapes).
• Cleaned up outdated Spark 3.2-only comments in both tests and a ClickHouse SparkPlan exec.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
backends-clickhouse/src/test/scala/org/apache/gluten/execution/GlutenClickHouseWholeStageTransformerSuite.scala	Removes dead spark32 helper used for version gating in tests.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/GlutenClickHouseTPCHBucketSuite.scala	Collapses Spark 3.2 conditionals to the Spark 3.3+ expectations and makes hasSortByCol unconditionally true.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/tpch/GlutenClickHouseTPCHParquetBucketSuite.scala	Removes Spark 3.2 branching in physical-plan assertions (keeps Spark 3.3+ behavior only).
backends-clickhouse/src/test/scala/org/apache/gluten/execution/GlutenClickHouseDeltaParquetWriteSuite.scala	Removes Spark 3.2 branching in optimize/vacuum-related assertions, keeping the Spark 3.3+ expected counts.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/tpcds/GlutenClickHouseTPCDSParquetAQESuite.scala	Updates comments to describe only the Spark 3.3+ plan shape.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/tpcds/GlutenClickHouseTPCDSParquetColumnarShuffleAQESuite.scala	Updates comments to describe only the Spark 3.3+ plan shape.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/mergetree/GlutenClickHouseMergeTreeWriteSuite.scala	Removes Spark 3.2 branches (e.g., always emits SORTED BY, keeps only Spark 3.3+ assertions).
backends-clickhouse/src/test/scala/org/apache/gluten/execution/mergetree/GlutenClickHouseMergeTreeOptimizeSuite.scala	Drops Spark 3.2 conditional assertions, keeping only Spark 3.3+ expected behaviors/counts.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/mergetree/GlutenClickHouseMergeTreeWriteOnHDFSSuite.scala	Removes Spark 3.2 conditional DDL/assertions; always uses Spark 3.3+ path.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/mergetree/GlutenClickHouseMergeTreeWriteOnHDFSWithRocksDBMetaSuite.scala	Removes Spark 3.2 conditional DDL/assertions; always uses Spark 3.3+ path.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/mergetree/GlutenClickHouseMergeTreeWriteOnS3Suite.scala	Removes Spark 3.2 conditional DDL/assertions; always uses Spark 3.3+ path.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/mergetree/GlutenClickHouseMergeTreePathBasedWriteSuite.scala	Removes Spark 3.2 guard around LocalTableScan plan assertion, keeping Spark 3.3+ expectation.
backends-clickhouse/src/test/scala/org/apache/gluten/execution/hive/GlutenClickHouseNativeWriteTableSuite.scala	Removes a stale Spark 3.2-specific comment.
backends-clickhouse/src/main/scala/org/apache/spark/sql/execution/RowToCHNativeColumnarExec.scala	Removes an outdated “For spark 3.2” comment above withNewChildInternal.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[LuciferYang]

cc @zzcclp @loneylee @taiyang-li @lgbo-ustc @zhztheplayer @jackylee-ch FYI

[zzcclp]

LGTM

[LuciferYang]

Thank you @zzcclp