Add missing header file to prevent compilation error.
In file included from /home/exl/Downloads/rp2040-doom/src/pd_render.cpp:71:
/home/exl/Downloads/rp2040-doom/src/pico/../whd_gen/statsomizer.h: In member function ‘void statsomizer::reset()’:
/home/exl/Downloads/rp2040-doom/src/pico/../whd_gen/statsomizer.h:36:20: error: ‘numeric_limits’ is not a member of ‘std’
36 | min = std::numeric_limits<int>::max();
| ^~~~~~~~~~~~~~
/home/exl/Downloads/rp2040-doom/src/pico/../whd_gen/statsomizer.h:36:35: error: expected primary-expression before ‘int’
36 | min = std::numeric_limits<int>::max();
| ^~~
/home/exl/Downloads/rp2040-doom/src/pico/../whd_gen/statsomizer.h:37:20: error: ‘numeric_limits’ is not a member of ‘std’
37 | max = std::numeric_limits<int>::min();
| ^~~~~~~~~~~~~~
/home/exl/Downloads/rp2040-doom/src/pico/../whd_gen/statsomizer.h:37:35: error: expected primary-expression before ‘int’
37 | max = std::numeric_limits<int>::min();
| ^~~
make[2]: *** [src/CMakeFiles/doom_tiny.dir/build.make:1938: src/CMakeFiles/doom_tiny.dir/pd_render.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:978: src/CMakeFiles/doom_tiny.dir/all] Error 2
make: *** [Makefile:91: all] Error 2
Add missing header file to prevent compilation error.