fix(catalyst): variable-length arrays

[NathanWalker]

Fixes the mac catalyst build when using Xcode 16.4. The following errors are now resolved:

NativeScript/runtime/Timers.cpp:166:27: error: variable length arrays in C++ are a Clang extension [-Werror,-Wvla-cxx-extension]
  166 |         Local<Value> argv[argc];

NativeScript/runtime/FFICall.h:46:62: error: variable length arrays in C++ are a Clang extension [-Werror,-Wvla-cxx-extension]
   46 |             this->StackSize = malloc_good_size(sizeof(void* [argsCount]));