Update cargo to 2024 edition (#842)

Some effects of this change:
- New formatting changes across many files. No functionality changes
should occur from that.
- Calls to `set_env` are considered unsafe, since this only happens in
tests we wrap them in `unsafe` blocks

codex-rs/core/src/codex.rs

@@ -9,18 +9,18 @@ use std::sync::Mutex;
 use anyhow::Context;
 use async_channel::Receiver;
 use async_channel::Sender;
-use codex_apply_patch::maybe_parse_apply_patch_verified;
-use codex_apply_patch::print_summary;
 use codex_apply_patch::AffectedPaths;
 use codex_apply_patch::ApplyPatchAction;
 use codex_apply_patch::ApplyPatchFileChange;
 use codex_apply_patch::MaybeApplyPatchVerified;
+use codex_apply_patch::maybe_parse_apply_patch_verified;
+use codex_apply_patch::print_summary;
 use fs_err as fs;
 use futures::prelude::*;
 use serde::Serialize;
 use serde_json;
-use tokio::sync::oneshot;
 use tokio::sync::Notify;
+use tokio::sync::oneshot;
 use tokio::task::AbortHandle;
 use tracing::debug;
 use tracing::error;
@@ -35,13 +35,13 @@ use crate::config::Config;
 use crate::config::ConfigOverrides;
 use crate::error::CodexErr;
 use crate::error::Result as CodexResult;
-use crate::exec::process_exec_tool_call;
 use crate::exec::ExecParams;
 use crate::exec::ExecToolCallOutput;
 use crate::exec::SandboxType;
+use crate::exec::process_exec_tool_call;
 use crate::flags::OPENAI_STREAM_MAX_RETRIES;
-use crate::mcp_connection_manager::try_parse_fully_qualified_tool_name;
 use crate::mcp_connection_manager::McpConnectionManager;
+use crate::mcp_connection_manager::try_parse_fully_qualified_tool_name;
 use crate::mcp_tool_call::handle_mcp_tool_call;
 use crate::models::ContentItem;
 use crate::models::FunctionCallOutputPayload;
@@ -57,9 +57,9 @@ use crate::protocol::Op;
 use crate::protocol::ReviewDecision;
 use crate::protocol::SandboxPolicy;
 use crate::protocol::Submission;
+use crate::safety::SafetyCheck;
 use crate::safety::assess_command_safety;
 use crate::safety::assess_patch_safety;
-use crate::safety::SafetyCheck;
 use crate::user_notification::UserNotification;
 use crate::util::backoff;
 use crate::zdr_transcript::ZdrTranscript;