Re licensing: LGPL-2.1-only

The goal is to manage to change the license from GPL to: LGPL-2.0-or-later

As Conservancy team explained, it does not make a lot of sense to use GPL and LGPL as dual licences.
Because when it is in a GPL project the LGPL upgrades to GPL.

docker run -v "${PWD}:/repo" mergestat/mergestat "SELECT author_name, count(*) FROM commits GROUP BY author_name ORDER BY count(*) DESC"
docker run -v "${PWD}:/repo" mergestat/mergestat "SELECT author_name, count(*), GROUP_CONCAT(substr(commits.hash, 1, 6)) as commits FROM commits GROUP BY author_name HAVING COUNT(*) < 10 ORDER BY count(*) DESC" > commits.txt
docker run -v "${PWD}:/repo" mergestat/mergestat "SELECT author_name, count(*), '' as commits FROM commits GROUP BY author_name HAVING COUNT(*) >= 10 ORDER BY count(*) DESC" > commits.txt

未指定目標檔案。首先檢視 repository 目前的授權條款，以及此 issue 中的貢獻者署名資訊，然後確認預期的授權條款是 LGPL-2.1-only 還是 LGPL-2.0-or-later。完成的標準是維護者已就一項授權條款達成共識，且所有受影響的授權聲明與貢獻要求都已一致更新。