remove legacy config

Author: liwensun

sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala

@@ -1711,15 +1711,6 @@ object SQLConf {
       .booleanConf
       .createWithDefault(false)
 
-  val LEGACY_PASS_PARTITION_BY_AS_OPTIONS =
-    buildConf("spark.sql.legacy.sources.write.passPartitionByAsOptions")
-      .internal()
-      .doc("Whether to pass the partitionBy columns as options in DataFrameWriter. " +
-        "Data source V1 now silently drops partitionBy columns for non-file-format sources; " +
-        "turning the flag on provides a way for these sources to see these partitionBy columns.")
-      .booleanConf
-      .createWithDefault(true)
-
   val NAME_NON_STRUCT_GROUPING_KEY_AS_VALUE =
     buildConf("spark.sql.legacy.dataset.nameNonStructGroupingKeyAsValue")
       .internal()

sql/core/src/main/scala/org/apache/spark/sql/DataFrameWriter.scala

@@ -316,12 +316,9 @@ final class DataFrameWriter[T] private[sql](ds: Dataset[T]) {
   }
 
   private def saveToV1Source(): Unit = {
-    if (SparkSession.active.sessionState.conf.getConf(
-      SQLConf.LEGACY_PASS_PARTITION_BY_AS_OPTIONS)) {
-      partitioningColumns.foreach { columns =>
-        extraOptions += (DataSourceUtils.PARTITIONING_COLUMNS_KEY ->
-          DataSourceUtils.encodePartitioningColumns(columns))
-      }
+    partitioningColumns.foreach { columns =>
+      extraOptions += (DataSourceUtils.PARTITIONING_COLUMNS_KEY ->
+        DataSourceUtils.encodePartitioningColumns(columns))
     }
 
     // Code path for data source v1.