fix: increase TXE callback timeout from 30s to 60s

The nft_contract TXE tests (transfer_to_private_internal_orchestration,
transfer_to_private_failure_not_an_owner) failed with 'Timeout waiting for
TypeScript callback for contract instance' due to CI resource contention.

The 30s default timeout is occasionally exceeded under heavy parallel
execution. Increasing to 60s provides more headroom without affecting
test correctness.

Author: AztecBot

barretenberg/cpp/src/barretenberg/nodejs_module/avm_simulate/ts_callback_utils.hpp

@@ -82,7 +82,7 @@ std::optional<std::vector<uint8_t>> invoke_ts_callback_with_promise(
     const Napi::ThreadSafeFunction& callback,
     const std::string& operation_name,
     std::function<void(Napi::Env, Napi::Function, std::shared_ptr<CallbackResults>)> call_js_function,
-    std::chrono::seconds timeout = std::chrono::seconds(30));
+    std::chrono::seconds timeout = std::chrono::seconds(60));
 
 /**
  * @brief Helper for callbacks that take a single string argument and return Buffer | undefined