[magnum] Proposing Jakub Darmach as core reviewer

Hello, I’d like to propose Jakub Darmach (jakub@stackhpc.com) as a core reviewer. He has spent quite a good deal of time to get unmaintained branches CI in a green state. He has also contributed some Heat driver patches in the past and is actively reviewing patches (also going the extra mile of updating these patches to be mergable when the author is not available/responsive). Michał Nasiadka mnasiadka@gmail.com