SIGSTKSZ is no longer a constant

[nicks2036]

• Compiler Used: gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0
• Operating System: Ubuntu 22.04.4 LTS
• Architecture (ARM/x86/32bit/64bit/etc): 64bit

Build process fails since SIGSTKSZ is no longer a constant. The value was used to define an array size and ir should be replaced:

/ChaiScript/unittests/catch.hpp:7441:45: error: size of array ‘altStackMem’ is not an integral constant-expression
7441 | char FatalConditionHandler::altStackMem[SIGSTKSZ] = {};

[totalgee]

The Catch unit testing library (header) needs to be updated to a newer version...