migrate to play 3.0.0

[mathieuancelin]

[JulienSt]

Hey, I actually am doing this right now on my fork. I just wanted to give you heads up, that there will be a massive merge request incoming.
It will update to scala3, pekko and play 3.0.0
You can see the changes here on this branch: https://github.com/JulienSt/otoroshi/tree/major-upgrade
But it does need the following merge for your dependency first: MAIF/wasm4s#6

[JulienSt]

This is the pr #2218