Improve release workflow

[npdgm]

Currently we can't release a chart if an other from the repository fails to build or wasn't pushed. Usually because files were altered and the version not bumped yet.

Perhaps we could use a matrix and run a job for each one. But also there's no need to trigger a workflow acting on all charts, so events would have to be filtered in some way. I don't like the idea of having multiple workflows but it would surely fix the situation for now.