feat: make it possible to set disable_response_storage = true in config.toml (#714)

https://github.com/openai/codex/pull/642 introduced support for the
`--disable-response-storage` flag, but if you are a ZDR customer, it is
tedious to set this every time, so this PR makes it possible to set this
once in `config.toml` and be done with it.

Incidentally, this tidies things up such that now `init_codex()` takes
only one parameter: `Config`.

codex-rs/exec/src/lib.rs

@@ -56,10 +56,14 @@ pub async fn run_main(cli: Cli) -> anyhow::Result<()> {
         // the user for approval.
         approval_policy: Some(AskForApproval::Never),
         sandbox_policy: sandbox_policy.map(Into::into),
+        disable_response_storage: if disable_response_storage {
+            Some(true)
+        } else {
+            None
+        },
     };
     let config = Config::load_with_overrides(overrides)?;
-    let (codex_wrapper, event, ctrl_c) =
-        codex_wrapper::init_codex(config, disable_response_storage).await?;
+    let (codex_wrapper, event, ctrl_c) = codex_wrapper::init_codex(config).await?;
     let codex = Arc::new(codex_wrapper);
     info!("Codex initialized with event: {event:?}");