Restore bridge networkstatus checks in chutney

This issue depends on the tor bridge descriptor upload fix in legacy/trac#33582 (moved), robust reachability self-tests in legacy/trac#33222 (moved), or bridge log checks in legacy/trac#34037 (moved).

In chutney networks, there's a race condition when bridges try to publish their descriptor to the bridge authority:

• bridges try to publish their descriptors before bootstrapping
• but bridges can't publish their descriptors, because they don't have enough directory info to build a circuit to the bridge authority

Also, bridges do not retry publishing their descriptor immediately after they bootstrap.

We can only do the networkstatus-bridges check on tor versions with the legacy/trac#33222 (moved) or legacy/trac#33582 (moved) fixes. So we'll need to check for:

• the next tor 0.4.4-alpha version, or
• an environmental variable that enables these tests.

We don't have to do these fixes, because it should be enough to test relay reachability. But we would risk breaking bridge reachability tests, and not knowing about it until after a release.

Also, the chutney workarounds seem to cause weird race conditions, which are time-consuming to diagnose and fix.