[SPARK-44402][SQL][TESTS] Add tests for schema pruning in delta-based…

… DELETEs

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

This PR adds tests for schema pruning for delta-based DELETEs, similar to the ones we have for MERGE and UPDATE.

### Why are the changes needed?

These changes are needed to verify schema pruning works as expected.

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

No.

### How was this patch tested?

This PR comes with tests.

Closes apache#41975 from aokolnychyi/spark-44402.

Authored-by: aokolnychyi <aokolnychyi@apple.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>

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

@@ -17,7 +17,7 @@
 
 package org.apache.spark.sql.connector
 
-import org.apache.spark.sql.AnalysisException
+import org.apache.spark.sql.{AnalysisException, Row}
 
 class DeltaBasedDeleteFromTableSuite extends DeleteFromTableSuiteBase {
 
@@ -59,4 +59,23 @@ class DeltaBasedDeleteFromTableSuite extends DeleteFromTableSuiteBase {
     }
     assert(exception.message.contains("Row ID attributes cannot be nullable"))
   }
+
+  test("delete with schema pruning") {
+    createAndInitTable("pk INT NOT NULL, id INT, country STRING, dep STRING",
+      """{ "pk": 1, "id": 1, "country": "uk", "dep": "hr" }
+        |{ "pk": 2, "id": 2, "country": "us", "dep": "software" }
+        |{ "pk": 3, "id": 3, "country": "canada", "dep": "hr" }
+        |""".stripMargin)
+
+    executeAndCheckScan(
+      s"DELETE FROM $tableNameAsString WHERE id <= 1",
+      // `pk` is used to encode deletes
+      // `id` is used in the condition
+      // `_partition` is used in the requested write distribution
+      expectedScanSchema = "pk INT, id INT, _partition STRING")
+
+    checkAnswer(
+      sql(s"SELECT * FROM $tableNameAsString"),
+      Row(2, 2, "us", "software") :: Row(3, 3, "canada", "hr") :: Nil)
+  }
 }