Drupalpod gitpod instance no longer requires ssh setup

Problem/Motivation

As far as I can tell, I don't need ssh access for anything I'd do in the Gitpod instance spun up by Drupalpod. It uses `https` git URLs, and everything "just works" with those. It's possible that somehow I'm grandfathered in and something is working by default, but I also haven't seen mentees at Drupalcon needing to set this up.

Proposed resolution

Remove the instructions about setting up ssh.

Remaining tasks

User interface changes

API changes

Data model changes