devel/catch: fix build with clang 19

Clang 19 has become more strict about C++ extensions, which results in:

 
/wrkdirs/usr/ports/devel/catch/work/Catch2-2.13.10/projects/SelfTest/UsageTests/Class.tests.cpp:83:1:
error: passing no argument for the '...' parameter of a variadic macro is a
C++20 extension [-Werror,-Wc++20-extensions]
     83 | TEMPLATE_TEST_CASE_METHOD(Template_Fixture, "A
TEMPLATE_TEST_CASE_METHOD based test run that succeeds", "[class][template]",
int, float, double) {
        | ^
  /wrkdirs/usr/ports/devel/catch/work/Catch2-2.13.10/include/catch.hpp:257:53:
note: expanded from macro 'TEMPLATE_TEST_CASE_METHOD'
    257 | #define TEMPLATE_TEST_CASE_METHOD( className, ... )
INTERNAL_CATCH_TEMPLATE_TEST_CASE_METHOD( className, __VA_ARGS__ )
        |                                                     ^
 
/wrkdirs/usr/ports/devel/catch/work/Catch2-2.13.10/include/internal/catch_test_registry.h:302:9:
note: expanded from macro 'INTERNAL_CATCH_TEMPLATE_TEST_CASE_METHOD'
    302 |         INTERNAL_CATCH_TEMPLATE_TEST_CASE_METHOD_2(
INTERNAL_CATCH_UNIQUE_NAME( C_A_T_C_H_T_E_M_P_L_A_T_E_T_E_S_T_C_L_A_S_S_ ),
INTERNAL_CATCH_UNIQUE_NAME( C_A_T_C_H_T_E_M_P_L_A_T_E_T_E_S_T_ ) , ClassName,
Name, Tags, typename T, __VA_ARGS__ )
        |         ^
 
/wrkdirs/usr/ports/devel/catch/work/Catch2-2.13.10/include/internal/catch_test_registry.h:279:13:
note: expanded from macro 'INTERNAL_CATCH_TEMPLATE_TEST_CASE_METHOD_2'
    279 |            
INTERNAL_CATCH_NTTP_GEN(INTERNAL_CATCH_REMOVE_PARENS(Signature))\