Replace ISC Dhcp through Kea

[kiarn]

Hello,

I've just seen that the support for the ISC Dhcp server is discontinued since 2022: https://www.isc.org/dhcp/.
It's not a big deal for our actual version, but we could discuss over a migration to kea for the next main version. This is just an issue as reminder for us.

Cheers

Arnaud