feat: enable CometLocalTableScanExec by default

spark/src/main/scala/org/apache/comet/CometConf.scala

@@ -273,7 +273,7 @@ object CometConf extends ShimCometConf {
   val COMET_EXEC_TAKE_ORDERED_AND_PROJECT_ENABLED: ConfigEntry[Boolean] =
     createExecEnabledConfig("takeOrderedAndProject", defaultValue = true)
   val COMET_EXEC_LOCAL_TABLE_SCAN_ENABLED: ConfigEntry[Boolean] =
-    createExecEnabledConfig("localTableScan", defaultValue = false)
+    createExecEnabledConfig("localTableScan", defaultValue = true)
 
   val COMET_NATIVE_COLUMNAR_TO_ROW_ENABLED: ConfigEntry[Boolean] =
     conf(s"$COMET_EXEC_CONFIG_PREFIX.columnarToRow.native.enabled")

spark/src/test/scala/org/apache/comet/exec/CometWindowExecSuite.scala

@@ -108,15 +108,7 @@ class CometWindowExecSuite extends CometTestBase {
         val cometShuffles = collect(df2.queryExecution.executedPlan) {
           case _: CometShuffleExchangeExec => true
         }
-        if (shuffleMode == "jvm" || shuffleMode == "auto") {
-          assert(cometShuffles.length == 1)
-        } else {
-          // we fall back to Spark for shuffle because we do not support
-          // native shuffle with a LocalTableScan input, and we do not fall
-          // back to Comet columnar shuffle due to
-          // https://github.com/apache/datafusion-comet/issues/1248
-          assert(cometShuffles.isEmpty)
-        }
+        assert(cometShuffles.length == 1)
       }
     }
   }