release_process: please clarify thawing packages
Originally created by @CyrilBrulebois on #16597 (Redmine)
Current post-release step:
1. [[Thaw the packages that were granted freeze exceptions|APT_repository/time-based snapshots#freeze-exceptions-post-release]].
I suppose this only makes sense for major releases? In which case, mentioning that explicitly would be good (again, peace of mind, etc.).