[SPARK-52950][SQL][TESTS] Enable ANSI mode in DataSourceV2StrategySuite

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

This PR proposes to explicitly enable ANSI mode in `DataSourceV2StrategySuite`.

### Why are the changes needed?

To fix the test failure when ANSI is off https://github.com/apache/spark/actions/runs/16485653304/job/46609769023

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

No, test-only.

### How was this patch tested?

Manually tested.

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

No.

Closes #51660 from HyukjinKwon/SPARK-52950.

Authored-by: Hyukjin Kwon <[email protected]>
Signed-off-by: Hyukjin Kwon <[email protected]>

Author: HyukjinKwon

sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/v2/DataSourceV2StrategySuite.scala

@@ -17,18 +17,24 @@
 
 package org.apache.spark.sql.execution.datasources.v2
 
+import org.apache.spark.SparkConf
 import org.apache.spark.sql.catalyst.analysis.UnresolvedAttribute
 import org.apache.spark.sql.catalyst.dsl.expressions._
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.plans.PlanTest
 import org.apache.spark.sql.catalyst.util.V2ExpressionBuilder
 import org.apache.spark.sql.connector.expressions.{Expression => V2Expression, FieldReference, GeneralScalarExpression, LiteralValue}
 import org.apache.spark.sql.connector.expressions.filter.{AlwaysFalse, AlwaysTrue, And => V2And, Not => V2Not, Or => V2Or, Predicate}
+import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.test.SharedSparkSession
 import org.apache.spark.sql.types.{BooleanType, DoubleType, IntegerType, LongType, StringType, StructField, StructType}
 import org.apache.spark.unsafe.types.UTF8String
 
 class DataSourceV2StrategySuite extends PlanTest with SharedSparkSession {
+
+  override protected def sparkConf: SparkConf = super.sparkConf
+    .set(SQLConf.ANSI_ENABLED, true)
+
   val attrInts = Seq(
     $"cint".int,
     $"`c.int`".int,