make tests pass cleanly in sandbox (#4067)

This changes the reqwest client used in tests to be sandbox-friendly,
and skips a bunch of other tests that don't work inside the
sandbox/without network.

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

@@ -24,7 +24,7 @@ use tempfile::TempDir;
 use tokio::time::timeout;
 use wiremock::MockServer;
 
-use core_test_support::non_sandbox_test;
+use core_test_support::skip_if_no_network;
 use mcp_test_support::McpProcess;
 use mcp_test_support::create_apply_patch_sse_response;
 use mcp_test_support::create_final_assistant_message_sse_response;
@@ -308,7 +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() {
-    non_sandbox_test!();
+    skip_if_no_network!();
 
     // Apparently `#[tokio::test]` must return `()`, so we create a helper
     // function that returns `Result` so we can use `?` in favor of `unwrap`.