Fix compilation on Ubuntu 24 (gcc 13.2)

[glennhickey]

This fixes some minor things that prevent this project from building on very recent systems.

These include (resolved with newest catch2):

In file included from /usr/include/signal.h:328,
from /home/hickey/dev/sublinear-Li-Stephens/src/test/catch.hpp:6442,
from /home/hickey/dev/sublinear-Li-Stephens/src/test/test.cpp:9:
/home/hickey/dev/sublinear-Li-Stephens/src/test/catch.hpp:6465:33: error: size of array ‘altStackMem’ is not an integral constant-expression
6465 | static char altStackMem[SIGSTKSZ];

and (resolved by adding cstdint include):

In file included from /home/hickey/dev/sublinear-Li-Stephens/src/haplotype_manager.hpp:6,
from /home/hickey/dev/sublinear-Li-Stephens/src/interface.cpp:1:
/home/hickey/dev/sublinear-Li-Stephens/src/haplotype_state_tree.hpp:18:29: error: ‘SIZE_MAX’ was not declared in this scope
18 | size_t initial_position = SIZE_MAX;
| ^~~~~~~~
/home/hickey/dev/sublinear-Li-Stephens/src/haplotype_state_tree.hpp:1:1: note: ‘SIZE_MAX’ is defined in header ‘’; did you forget to ‘#include ’?