[SPARK-58996][SQL][FOLLOWUP] Fix the subset join key test for the branch-4.3 backport

Sets `spark.sql.sources.v2.bucketing.requireAllClusterKeysForCoPartition` to
false in the "partially clustered subset-key join keeps its join key
positions" test, which is what every other subset test in this suite already
does on this branch.

Without the config `createKeyedShuffleSpec` refuses the subset shape (join
key `id` against partition keys `(extra, id)`), both sides are shuffled, and
the no-shuffle assertion fails. On master the test plans without the config
because SPARK-58558 relaxed the check from exact key match to key coverage;
it is not on this branch.

No user-facing change.

Assisted-by: Claude Fable 5

Author: ulysses-you

sql/core/src/test/scala/org/apache/spark/sql/connector/KeyGroupedPartitioningSuite.scala

@@ -3669,6 +3669,10 @@ class KeyGroupedPartitioningSuite extends DistributionAndOrderingSuiteBase with
     sql("INSERT INTO testcat.ns.np2 VALUES (7, 'y')")
 
     withSQLConf(
+        // SPARK-58558 (4.4.0) relaxed `createKeyedShuffleSpec` from exact key match to key
+        // coverage; it is not in this branch, so the subset shape needs the config off, as every
+        // other subset test here does.
+        SQLConf.REQUIRE_ALL_CLUSTER_KEYS_FOR_CO_PARTITION.key -> "false",
         SQLConf.V2_BUCKETING_PUSH_PART_VALUES_ENABLED.key -> "true",
         SQLConf.V2_BUCKETING_PARTIALLY_CLUSTERED_DISTRIBUTION_ENABLED.key -> "true",
         SQLConf.V2_BUCKETING_ALLOW_KEYS_SUBSET_OF_PARTITION_KEYS.key -> "true",