change disco github app name to include name of server

[gregsadetsky]

https://github.com/letsdiscodev/disco-daemon/blob/main/disco/endpoints/githubapps.py#L128

per @robsimmons's suggestion

[gregsadetsky]

note that the max length of github app names is 34 chars, so we must truncate "Disco @(server) (random name)" to fit that length

[robsimmons]

Is the random name actually necessary? I was assuming it was there because the same app name would cause some kind of problem.

[gregsadetsky]

it's unfortunately necessary because the app name must be globally unique to github

https://docs.github.com/en/apps/creating-github-apps/registering-a-github-app/registering-a-github-app#registering-a-github-app

[gregsadetsky]

just following up, we'd like to move to

Disco (server) (some hex)

and truncate the server name. and not use random words, but a short hex string instead.