`inbound_call_drop_connecting_ice_failed_first` is flaky

[brjsp]

The test inbound_call_drop_connecting_ice_failed_first is flaky on Linux, sometimes failing with:

[ 250s] ---- inbound_call_drop_connecting_ice_failed_first stdout ----
[ 250s] thread 'inbound_call_drop_connecting_ice_failed_first' panicked at src/rust/tests/incoming.rs:375:5:
[ 250s] assertion left == right failed
[ 250s] left: 1
[ 250s] right: 0

This is ringrtc version 2.39.0