Update CI image of current release branch after each release
See !1219 (comment 46451). The problem is that the v0.8 image is outdated, because it was built manually for the last release (%0.8.2), and contains an old flux version. %0.8.2 updated flux to 0.30.2 and therefor we need to build a new image containing this flux version.
And we can't just run a pipeline for the v0.8 branch, it's forbidden by our CI workflow rules:
Edited by Varac