Update CODEOWNERS to replace TEF representative

[javierlozallu]

Hi all,

It has been a pleasure to be part of this initiative where I have learned a lot of things and met amazing people from telcos and companies from all over the world, now I am taking on a new challenge in my career and my colleague @JoseMConde will lead the meetings, so he must be added in the CODEOWNERS file.

Thank you very much, all the best!
Javier Loza