remove self from core devs list

Hey y'all 👋 

I just saw my name in the governance doc under "core devs" - I hadn't realise I'd been added (I'd originally been invited to join as triager)

Although I'd like to think I've been helpful, I don't think anything I've done warrants being made core dev. Furthermore, I've not been active in the core codebase for > 1 year

I'd like to emphasise that I'm still happy to help out with occasional reviews and docs, and that I have a huge amount of respect for the PyMC project and its community - I just don't think I belong on this list

Author: MarcoGorelli

GOVERNANCE.md

@@ -198,7 +198,6 @@ Contributors don't need to be part of any dedicated team.
 * George Ho (dev)
 * Junpeng Lao (dev, discourse)
 * Luciano Paz (dev - PyMC Labs)
-* Marco E. Gorelli (dev, docs)
 * Martina Cantaro (docs)
 * Maxim Kochurov (dev - PyMC Labs)
 * Meenal Jhajharia (docs)