chore: remove @guillaumemichel from maintainers

Removing myself from the maintainers list, since I have less time to invest to the project. I will spend more time working on IPFS in Go, so I won't be far away :)

Feel free to continue tagging me for `kad` reviews.

Pull-Request: #5834.

README.md

@@ -78,7 +78,6 @@ Conduct](https://github.com/ipfs/community/blob/master/code-of-conduct.md).
 
 (In alphabetical order.)
 
-- Guillaume Michel ([@guillaumemichel](https://github.com/guillaumemichel))
 - João Oliveira ([@jxs](https://github.com/jxs))
 
 ## Notable users