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/cli/src/linux-sandbox/main.rs

@@ -7,9 +7,9 @@ fn main() -> anyhow::Result<()> {
 #[cfg(target_os = "linux")]
 fn main() -> anyhow::Result<()> {
     use clap::Parser;
+    use codex_cli::LandlockCommand;
     use codex_cli::create_sandbox_policy;
     use codex_cli::landlock;
-    use codex_cli::LandlockCommand;
 
     let LandlockCommand {
         full_auto,