Fix thread settings clippy failure (#23724)

## Why

`main` picked up two small Rust build failures after nearby merges:

- #23507 added a real handler for
`ServerNotification::ThreadSettingsUpdated`, but the same variant was
still listed in the ignored-notification match arm. Full Clippy runs
treat the resulting unreachable-pattern warning as an error.
- #23666 added `turn_id` and `truncation_policy` to
`codex_tools::ToolCall`, while the goal extension backend test fixtures
from the goal-extension work still used the old shape. That left
`codex-goal-extension` tests unable to compile once the branches met on
`main`.

## What changed

Removed the duplicate `ThreadSettingsUpdated` match pattern from
`tui/src/chatwidget/protocol.rs`.

Updated the goal extension test `tool_call` helper to populate the new
`ToolCall` fields, and reused that helper for the one direct literal
that still had the old field list.

## Verification

- `just fix -p codex-tui`
- `cargo test -p codex-goal-extension`

codex-rs/tui/src/chatwidget/protocol.rs

@@ -220,7 +220,6 @@ impl ChatWidget {
             | ServerNotification::AccountRateLimitsUpdated(_)
             | ServerNotification::ThreadStarted(_)
             | ServerNotification::ThreadStatusChanged(_)
-            | ServerNotification::ThreadSettingsUpdated(_)
             | ServerNotification::ThreadArchived(_)
             | ServerNotification::ThreadUnarchived(_)
             | ServerNotification::RawResponseItemCompleted(_)