Fix memory leak if sk_push fails

If it fails, then the duplicated item is not freed.
Solve it by making sure the push cannot fail by reserving the necessary
stack size upfront.

Example Valgrind trace:
```
14,009 (384 direct, 13,625 indirect) bytes in 1 blocks are definitely lost in loss record 27,287 of 27,373
  malloc (at /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
  CRYPTO_zalloc (at /usr/lib/x86_64-linux-gnu/libcrypto.so.3)
  <unknown stack frame>
  ASN1_item_new (at /usr/lib/x86_64-linux-gnu/libcrypto.so.3)
 *ossl_x509_alloc (ossl_x509cert.c:97)
  <unknown stack frame>
  rb_class_new_instance_pass_kw (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  <unknown stack frame>
  <unknown stack frame>
  <unknown stack frame>
  <unknown stack frame>
  rb_vm_exec (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  <unknown stack frame>
  <unknown stack frame>
  rb_catch_obj (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  <unknown stack frame>
  <unknown stack frame>
  <unknown stack frame>
  rb_vm_exec (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  rb_yield (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  rb_ary_each (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  <unknown stack frame>
  <unknown stack frame>
  <unknown stack frame>
  rb_vm_exec (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  rb_yield (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  rb_ary_each (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  <unknown stack frame>
  <unknown stack frame>
  <unknown stack frame>
  rb_vm_exec (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  rb_yield (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  rb_ary_each (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  <unknown stack frame>
  <unknown stack frame>
  <unknown stack frame>
  rb_vm_exec (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  rb_yield (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  rb_ary_each (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  <unknown stack frame>
  <unknown stack frame>
  <unknown stack frame>
  rb_vm_exec (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  <unknown stack frame>
  <unknown stack frame>
  rb_catch_obj (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
  <unknown stack frame>
  <unknown stack frame>
  <unknown stack frame>
  rb_vm_exec (at /usr/lib/x86_64-linux-gnu/libruby-3.2.so.3.2.3)
```

Author: ndossche

ext/openssl/ossl.c

@@ -34,7 +34,11 @@ ossl_##name##_ary2sk0(VALUE ary)                                \
                        " of class ##type##");                   \
         }                                                       \
         x = dup(val); /* NEED TO DUP */                         \
-        sk_##type##_push(sk, x);                                \
+        if (!sk_##type##_push(sk, x)) {                         \
+            type##_free(x);                                     \
+            sk_##type##_pop_free(sk, type##_free);              \
+            ossl_raise(eOSSLError, NULL);                       \
+        }                                                       \
     }                                                           \
     return (VALUE)sk;                                           \
 }                                                               \