Use new builtin defer

[izissise]

Hello,
It seems gcc and clang now have a builtins defer https://gustedt.wordpress.com/2026/02/15/defer-available-in-gcc-and-clang/

Would be nice to add :)

Thanks,
Hugues

[aartaka]

I've removed Pretty C defer for now, until I figure out this new development. PR welcome, might need some time with it 😌