Draft: community/tor: disable dirauth build
There is no need to build support for running a directory authority in Alpine's tor package, since:
- There are currently 9 hardcoded dirauth in the tor network, and the odds of having a new one are close to inexistant.
- Not a single dirauth is running on Alpine Linux
- Since there are only 9 instances of dirauth in prod, the code to run one isn't as battle-tested as the regular relay one (the network has currently a bit less than 8000 relays)
- This would allow to reduce the size of the binary, and we all love that.