Update torrc to encourage use of BridgeDistribution
Bridge operators should generally publish their descriptors except for rare cases, and instead use the BridgeDistribution none setting to prevent their bridge from being distributed by BridgeDB.
Closes #40430 (closed)
Note: I'm not sure what to do about src/config/torrc.minimal.in vs src/config/torrc.minimal.in-staging so I looked at previous commits for guidance.