compile error building tests on apple M1 machine

[springmeyer]

Seeing:

In file included from /Users/sehome/projects/selene/test/selene/Catch.cpp:6:
/Users/sehome/projects/selene/external/Catch2/single_include/catch2/catch.hpp:7937:13: error: unrecognized instruction mnemonic, did you mean: bit, cnt, hint, ins, not?
            CATCH_BREAK_INTO_DEBUGGER();
            ^
/Users/sehome/projects/selene/external/Catch2/single_include/catch2/catch.hpp:7651:79: note: expanded from macro 'CATCH_BREAK_INTO_DEBUGGER'
    #define CATCH_BREAK_INTO_DEBUGGER() []{ if( Catch::isDebuggerActive() ) { CATCH_TRAP(); } }()
                                                                              ^
./projects/selene/external/Catch2/single_include/catch2/catch.hpp:7630:34: note: expanded from macro 'CATCH_TRAP'
    #define CATCH_TRAP() __asm__("int $3\n" : : ) /* NOLINT */
                                 ^
<inline asm>:1:2: note: instantiated into assembly here
        int $3
        ^
1 error generated.

It looks like this is a bug in Catch2, which can be fixed by upgrading the library submodule: catchorg/Catch2#1127