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/mcp-types/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "mcp-types"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
 serde = { version = "1", features = ["derive"] }

codex-rs/mcp-types/src/lib.rs

@@ -5,9 +5,9 @@
 // ```shell
 // ./generate_mcp_types.py
 // ```
-use serde::de::DeserializeOwned;
 use serde::Deserialize;
 use serde::Serialize;
+use serde::de::DeserializeOwned;
 use std::convert::TryFrom;
 
 pub const MCP_SCHEMA_VERSION: &str = "2025-03-26";

codex-rs/mcp-types/tests/initialize.rs

@@ -2,10 +2,10 @@ use mcp_types::ClientCapabilities;
 use mcp_types::ClientRequest;
 use mcp_types::Implementation;
 use mcp_types::InitializeRequestParams;
+use mcp_types::JSONRPC_VERSION;
 use mcp_types::JSONRPCMessage;
 use mcp_types::JSONRPCRequest;
 use mcp_types::RequestId;
-use mcp_types::JSONRPC_VERSION;
 use serde_json::json;
 
 #[test]