Drop an ignored attribute

GCC 13.3.0 (Ubuntu 24.04) emits the following warning:

../symbol.c: In function ‘rb_id_attrset’:
../symbol.c:175:9: warning: ‘nonstring’ attribute ignored on objects of type ‘const char[][8]’ [-Wattributes]
  175 |         RBIMPL_ATTR_NONSTRING() static const char id_types[][8] = {
      |         ^~~~~~~~~~~~~~~~~~~~~

1 files changed, 1 insertions, 1 deletions

diff --git a/symbol.c b/symbol.c
index 8ba0b818a8..12dea88158 100644
--- a/symbol.c
+++ b/symbol.c
@@ -172,7 +172,7 @@ rb_id_attrset(ID id)
 
     /* make new symbol and ID */
     if (!(str = lookup_id_str(id))) {
-        RBIMPL_ATTR_NONSTRING() static const char id_types[][8] = {
+        static const char id_types[][8] = {
             "local",
             "instance",
             "invalid",