SSH public keys are well known to be safe to make available publicly, for example you can get any GitHub users public keys by just appending .keys to their username, E.G.https://github.com/evilhamsterman.keys. In conjunction with#10487 this could allow for easy automation to pull user's public keys from coder to install in git and over VCS systems, remote servers, or even with a tool likeage encrypt data to be sent to a user.

Along with making the key more available I would also rename the API endpoint as it could be used for more than just git.