[ruby/digest] stringop-overread warning is since GCC 11

ruby/digest@d16853fe8c

Author: nobu

ext/digest/sha1/sha1.c

@@ -234,7 +234,7 @@ void SHA1_Update(SHA1_CTX *context, const uint8_t *data, size_t len)
 	SHA1_Transform(context->state, context->buffer);
 	for ( ; i + 63 < len; i += 64) {
 	    RB_DIGEST_WARNING_PUSH();
-#if defined(__GNUC__) && !defined(__clang__)
+#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ >= 11
 	    RB_DIGEST_WARNING_IGNORED(-Wstringop-overread);
 #endif
 	    SHA1_Transform(context->state, &data[i]);