fix for warning with snprintf use in test case

[JacobBarthelmeh]

gcc version 15.2.0 (GCC)

Fixes the following warning with --enable-all build:

apps/wolfsshd/test/test_configuration.c: In function 'CleanupWildcardTest':
./wolfssh/port.h:582:55: error: '%s' directive output may be truncated writing up to 1023 bytes into a region of size 506 [-Werror=format-truncation=]
  582 |         #define WSNPRINTF(s,n,f,...) snprintf((s),(n),(f),##__VA_ARGS__)
      |                                                       ^~~
apps/wolfsshd/test/test_configuration.c:46:17: note: in expansion of macro 'WSNPRINTF'
   46 |                 WSNPRINTF(filepath, sizeof filepath, "%s%s",
      |                 ^~~~~~~~~
./wolfssh/port.h:582:38: note: '__builtin_snprintf' output between 17 and 1040 bytes into a destination of size 522
  582 |         #define WSNPRINTF(s,n,f,...) snprintf((s),(n),(f),##__VA_ARGS__)
      |                                      ^~~~~~~~
apps/wolfsshd/test/test_configuration.c:46:17: note: in expansion of macro 'WSNPRINTF'
   46 |                 WSNPRINTF(filepath, sizeof filepath, "%s%s",
      |                 ^~~~~~~~~
cc1: all warnings being treated as errors
make[1]: *** [apps/wolfsshd/test/test_configuration-test_configuration.o] Error 1