oj v3.7.9 doesn't compile with clang 16:

```
custom.c:357:23: error: incompatible function pointer types passing 'int (VALUE, VALUE, Out)' (aka 'int (unsigned long, unsigned long, struct _out *)') to parameter of type 'int (*)(VALUE, VALUE, VALUE)' (aka 'int (*)(unsigned long, unsigned long, unsigned long)') [-Wincompatible-function-pointer-types]
        rb_hash_foreach(obj, hash_cb, (VALUE)out);
                             ^~~~~~~
/Users/stanhu/.asdf/installs/ruby/3.0.6/include/ruby-3.0.0/ruby/internal/intern/hash.h:33:35: note: passing argument to parameter here
void rb_hash_foreach(VALUE, int (*)(VALUE, VALUE, VALUE), VALUE);
                                  ^
custom.c:664:26: error: incompatible function pointer types passing 'int (ID, VALUE, Out)' (aka 'int (unsigned long, unsigned long, struct _out *)') to parameter of type 'int (*)(ID, VALUE, st_data_t)' (aka 'int (*)(unsigned long, unsigned long, unsigned long)') [-Wincompatible-function-pointer-types]
    rb_ivar_foreach...