This fixes a flaky `turn_start_shell_zsh_fork_executes_command_v2` test.
The interrupt path can race with the follow-up `/responses` request that
reports the aborted tool call, so the test now allows that extra no-op
response instead of assuming there will only ever be one request. The
assertions still stay focused on the behavior the test actually cares
about: starting the zsh-forked command correctly.
Testing:
- `just fmt`
- `cargo test -p codex-app-server --test all
suite::v2::turn_start_zsh_fork::turn_start_shell_zsh_fork_executes_command_v2
-- --exact --nocapture`
Owen Lin
6c98a59dbd