Cache volumes keep dependency directories between CI jobs. Until now, only successful jobs on the default branch saved their changes, so teams that don't run CI on the default branch after every merge saw their caches fall behind during the day.
You can now choose which branches save. Open Runners → Profiles, edit the profile your workflows use in runs-on:, and expand Save cache from. Add branch names or patterns such as release/*, or * to let every branch in the repository save. The list applies to every cache volume used by jobs on that profile, including the new volumes you get when your cache key changes.
Until you change it, a profile follows each repository's default branch, so existing workflows keep working as before. Pull requests from forks never save. See the cache volumes guide for details.