fix: Scala 2.13 compilation errors and unused parameter warnings

- Fix type mismatch by adding .toSeq to ArrayBuffer in CometNativeCompaction
- Replace asScala on CloseableIterator with explicit while loop for Scala 2.13 compatibility
- Remove unused warehouseDir parameters and filesBefore/nativeFilesAfter variables
- Remove unused tableLocation parameter from buildCompactionConfig

Author: Shekharrajak

spark/src/test/scala/org/apache/comet/CometIcebergCompactionBenchmarkTest.scala

@@ -144,11 +144,7 @@ class CometIcebergCompactionBenchmarkTest extends CometTestBase {
              l_quantity DOUBLE, l_extendedprice DOUBLE, l_discount DOUBLE, l_tax DOUBLE,
              l_returnflag STRING, l_linestatus STRING"""
         val (lSpark, lNative, lSpeedup) =
-          runTableBenchmark(
-            "lineitem",
-            lineitemSchema,
-            numFragments,
-            rowsPerFragment)
+          runTableBenchmark("lineitem", lineitemSchema, numFragments, rowsPerFragment)
         println(f"${"lineitem"}%-15s $lSpark%12d $lNative%12d ${lSpeedup}%9.2fx")
 
         // Orders benchmark
@@ -165,11 +161,7 @@ class CometIcebergCompactionBenchmarkTest extends CometTestBase {
           """c_custkey BIGINT, c_name STRING, c_address STRING, c_nationkey BIGINT,
              c_phone STRING, c_acctbal DOUBLE, c_mktsegment STRING, c_comment STRING"""
         val (cSpark, cNative, cSpeedup) =
-          runTableBenchmark(
-            "customer",
-            customerSchema,
-            numFragments,
-            rowsPerFragment)
+          runTableBenchmark("customer", customerSchema, numFragments, rowsPerFragment)
         println(f"${"customer"}%-15s $cSpark%12d $cNative%12d ${cSpeedup}%9.2fx")
 
         println("-" * 60)

spark/src/test/scala/org/apache/spark/sql/comet/CometNativeCompaction.scala

@@ -132,11 +132,8 @@ class CometNativeCompaction(spark: SparkSession) extends Logging {
         s"Processing file group ${groupIndex + 1}/${fileGroups.size} " +
           s"with ${group.size} files")
 
-      val compactionConfig = buildCompactionConfig(
-        tableConfig,
-        group,
-        targetFileSizeBytes,
-        compression)
+      val compactionConfig =
+        buildCompactionConfig(tableConfig, group, targetFileSizeBytes, compression)
       val result = executeNativeCompaction(compactionConfig)
 
       result match {