[SPARK-50380][SQL][TESTS][FOLLOWUP] Enable ANSI for conditional branches with error expression test

### What changes were proposed in this pull request?

This is a follow-up to recover non-ANSI CI.
- #48918

### Why are the changes needed?

The original PR broke non-ANSI CI because the test case assumes ANSI setting.

- https://github.com/apache/spark/actions/runs/11964792566
- https://github.com/apache/spark/actions/runs/11982859814

### Does this PR introduce _any_ user-facing change?

No, this is a test-only change.

### How was this patch tested?

Manual tests.

**BEFORE**

```
$ SPARK_ANSI_SQL_MODE=false build/sbt "catalyst/testOnly *.ReorderAssociativeOperatorSuite -- -z SPARK-50380"
...
[info] *** 1 TEST FAILED ***
[error] Failed tests:
[error] 	org.apache.spark.sql.catalyst.optimizer.ReorderAssociativeOperatorSuite
[error] (catalyst / Test / testOnly) sbt.TestsFailedException: Tests unsuccessful
[error] Total time: 8 s, completed Nov 23, 2024, 11:50:45 AM
```

**AFTER**

```
$ SPARK_ANSI_SQL_MODE=false build/sbt "catalyst/testOnly *.ReorderAssociativeOperatorSuite -- -z SPARK-50380"
...
[info] ReorderAssociativeOperatorSuite:
[info] - SPARK-50380: conditional branches with error expression (508 milliseconds)
[info] Run completed in 1 second, 413 milliseconds.
[info] Total number of tests run: 1
[info] Suites: completed 1, aborted 0
[info] Tests: succeeded 1, failed 0, canceled 0, ignored 0, pending 0
[info] All tests passed.
[success] Total time: 11 s, completed Nov 23, 2024, 11:51:34 AM
```

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #48943 from dongjoon-hyun/SPARK-50380.

Authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: dongjoon-hyun

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/ReorderAssociativeOperatorSuite.scala

@@ -24,6 +24,7 @@ import org.apache.spark.sql.catalyst.expressions.aggregate.Count
 import org.apache.spark.sql.catalyst.plans.{Inner, PlanTest}
 import org.apache.spark.sql.catalyst.plans.logical.{LocalRelation, LogicalPlan}
 import org.apache.spark.sql.catalyst.rules.RuleExecutor
+import org.apache.spark.sql.internal.SQLConf
 
 class ReorderAssociativeOperatorSuite extends PlanTest {
 
@@ -109,15 +110,17 @@ class ReorderAssociativeOperatorSuite extends PlanTest {
   }
 
   test("SPARK-50380: conditional branches with error expression") {
-    val originalQuery1 = testRelation.select(If($"a" === 1, 1L, Literal(1).div(0) + $"b")).analyze
-    val optimized1 = Optimize.execute(originalQuery1)
-    comparePlans(optimized1, originalQuery1)
-
-    val originalQuery2 = testRelation.select(
-      If($"a" === 1, 1, ($"b" + Literal(Int.MaxValue)) + 1).as("col")).analyze
-    val optimized2 = Optimize.execute(originalQuery2)
-    val correctAnswer2 = testRelation.select(
-      If($"a" === 1, 1, $"b" + (Literal(Int.MaxValue) + 1)).as("col")).analyze
-    comparePlans(optimized2, correctAnswer2)
+    withSQLConf(SQLConf.ANSI_ENABLED.key -> true.toString) {
+      val originalQuery1 = testRelation.select(If($"a" === 1, 1L, Literal(1).div(0) + $"b")).analyze
+      val optimized1 = Optimize.execute(originalQuery1)
+      comparePlans(optimized1, originalQuery1)
+
+      val originalQuery2 = testRelation.select(
+        If($"a" === 1, 1, ($"b" + Literal(Int.MaxValue)) + 1).as("col")).analyze
+      val optimized2 = Optimize.execute(originalQuery2)
+      val correctAnswer2 = testRelation.select(
+        If($"a" === 1, 1, $"b" + (Literal(Int.MaxValue) + 1)).as("col")).analyze
+      comparePlans(optimized2, correctAnswer2)
+    }
   }
 }