Set bridge running status on a timer?
In #24490 (moved), we changed dirserv_set_bridges_running() to happen immediately before writing to disk, rather than updating each bridge with each getinfo. That's good for the typical use case, but it makes GETINFO less accurate than it was before. Perhaps we should change dirserv_set_bridges_running() to use a timer instead.
If we do this, we should do it after #30293 (moved) is merged, since that is likely to change the pattern for periodic events.