NHF Iceberg Table: Commit instead of overwrite

[quercoak]

The script to add NHF to iceberg table may be overwriting the table data instead of adding a new commit and commit message. Script needs to be adjusted to add new commits to table with commit message of NHF version number.

https://github.com/NGWPC/icefabric/blob/main/tools/iceberg/build_nhf.py