public static TableSchema getPhysicalSchemaForDimTable(TableSchema tableSchema) {
    TableSchema.Builder builder = filter(tableSchema, TableColumn::isPhysical);
    tableSchema.getWatermarkSpecs().forEach(builder::watermark);
    return builder.build();
  }
Add watermark info to help {@link FlinkSource} and {@link MixedFormatDynamicSource} distinguish
the watermark field. For now, it only be used in the case of mixed-format table as dim-table.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/FlinkSchemaUtil.java