fix: increase timeout for test_dev_null_write (#933)

After updating this test in https://github.com/openai/codex/pull/923, I
have been getting some timeouts with this test in CI, so increasing the
timeout to match that of `test_writable_root`:


327cf41f0f/codex-rs/core/src/landlock.rs (L211-L213)

codex-rs/core/src/landlock.rs

@@ -194,7 +194,14 @@ mod tests {
 
     #[tokio::test]
     async fn test_dev_null_write() {
-        run_cmd(&["bash", "-lc", "echo blah > /dev/null"], &[], 200).await;
+        run_cmd(
+            &["bash", "-lc", "echo blah > /dev/null"],
+            &[],
+            // We have seen timeouts when running this test in CI on GitHub,
+            // so we are using a generous timeout until we can diagnose further.
+            1_000,
+        )
+        .await;
     }
 
     #[tokio::test]