Fix GCC -Wformat-truncation error in legacy log adapter

Widen snprintf buffer from 1024 to 2048 bytes in mju_defaultLogHandler
to avoid truncation warning when formatting "func: subject".

PiperOrigin-RevId: 930823501
Change-Id: I0b2246f23c44e983bea76976b684d2efdfdff29c

src/engine/engine_util_errmem.c

@@ -245,13 +245,13 @@ static void mju_defaultLogHandler(const mjLogMessage* msg) {
   }
 
   if (msg->level == mjLOG_ERROR && mju_user_error) {
-    char buf[1024];
+    char buf[2048];
     mju_user_error(mju_legacy_text(msg, buf, sizeof(buf)));
     return;
   }
 
   if (msg->level == mjLOG_WARNING && mju_user_warning) {
-    char buf[1024];
+    char buf[2048];
     mju_user_warning(mju_legacy_text(msg, buf, sizeof(buf)));
     return;
   }