pybridge: Restore cockpit.beiboot debug logging

Commit ba93304 dropped the executable wrapper around beiboot.py,
which broke `COCKPIT_DEBUG=cockpit.beiboot`. Hardcode the name to bring
it back.

src/cockpit/beiboot.py

@@ -40,7 +40,7 @@
 from cockpit.router import Router, RoutingRule
 from cockpit.transports import StdioTransport
 
-logger = logging.getLogger(__name__)
+logger = logging.getLogger('cockpit.beiboot')
 
 
 def ensure_ferny_askpass() -> Path: