Update lifecycle.md: license must be AGPLv3

Raised on the chat: https://chat.civicrm.org/civicrm/pl/qk8tyddkmjbz7k11g6dsks66fc (extension channel)

Reviewed extensions have always been AGPLv3 historically, and we want to keep things simple for site administrators.

(this does not mean that non-AGPLv3 extensions cannot be in the directory, only applies to reviewed/recommended extensions)