COMMITS_HEAD_COUNT does not appear in 'pga list'

As it is documented in https://docs.sourced.tech/datasets/publicgitarchive/web/md/index

|  Column name | Column description  |
|---|---|
|COMMITS_HEAD_COUNT|Number of commits on the history obtained by the commit pointed by default HEAD. The output is the same as `git rev-list --count HEAD`.|

`COMMITS_HEAD_COUNT` does not appear in `pga list`