Build fails: error: variable length arrays in C++ are a Clang extension [-Werror,-Wvla-cxx-extension]

```
olad/Olad.cpp:85:23: error: variable length arrays in C++ are a Clang extension [-Werror,-Wvla-cxx-extension]
   85 |   char *original_argv[original_argc];
      |                       ^~~~~~~~~~~~~
```

[log](https://pkg-status.freebsd.org/beefy18/data/main-amd64-default/pe8c02a572f87_sb37333899bd/logs/ola-0.10.9_4.log)

Version: 0.10.9
clang-19
FreeBSD 15.0-CURRENT