Add non_sandbox_test helper (#3880)

Makes tests shorter

codex-rs/mcp-server/tests/suite/codex_tool.rs

@@ -24,6 +24,7 @@ use tempfile::TempDir;
 use tokio::time::timeout;
 use wiremock::MockServer;
 
+use core_test_support::non_sandbox_test;
 use mcp_test_support::McpProcess;
 use mcp_test_support::create_apply_patch_sse_response;
 use mcp_test_support::create_final_assistant_message_sse_response;
@@ -307,12 +308,7 @@ async fn patch_approval_triggers_elicitation() -> anyhow::Result<()> {
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn test_codex_tool_passes_base_instructions() {
-    if std::env::var(CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR).is_ok() {
-        println!(
-            "Skipping test because it cannot execute when network is disabled in a Codex sandbox."
-        );
-        return;
-    }
+    non_sandbox_test!();
 
     // Apparently `#[tokio::test]` must return `()`, so we create a helper
     // function that returns `Result` so we can use `?` in favor of `unwrap`.