As discussed in apache/arrow#47113 , this package is writing the deprecated BIT_PACKING encoding to the column metadata and the DataPageHeader. This is only seems to happens when rep/def levels are empty. I think this is where it's happening:

public class DevNullValuesWriter extends ValuesWriter {
  ....
  public Encoding getEncoding() {
    return BIT_PACKED;
  }
}

Wouldn't it make sense to just return RLE?

I've seen this in parquet-java 1.15.1 and Overture Maps files using 1.13.1.