perl_c.c: Fix declaration of argv

perl_c.c: Fix declaration of argv

In GCC 14:

perl_c.c: In function ‘perl4caml_init’:
perl_c.c:97:25: error: passing argument 2 of ‘Perl_sys_init’ from incompatible pointer type [-Wincompatible-pointer-types]
   97 |   PERL_SYS_INIT (&argc, &argv);
      |                         ^~~~~
      |                         |
      |                         char * (*)[5]
/usr/lib64/perl5/CORE/perl.h:3608:61: note: in definition of macro ‘PERL_SYS_INIT’
 3608 | #define PERL_SYS_INIT(argc, argv)       Perl_sys_init(argc, argv)
      |                                                             ^~~~
In file included from /usr/lib64/perl5/CORE/perl.h:6188:
/usr/lib64/perl5/CORE/proto.h:4992:34: note: expected ‘char ***’ but argument is of type ‘char * (*)[5]’
 4992 | Perl_sys_init(int *argc, char ***argv);
      |                          ~~~~~~~~^~~~