wayland/textinput_v2: copy the data instead of assuming ownership

The life time of the wl_array is limited to the callback, afterwards it's
a dangling pointer

BUG: 481239

src/wayland/inputmethod_v1.cpp

@@ -110,7 +110,7 @@ public:
     }
     void zwp_input_method_context_v1_modifiers_map(Resource *, wl_array *map) override
     {
-        const auto mods = QByteArray::fromRawData(static_cast<const char *>(map->data), map->size);
+        const auto mods = QByteArray(static_cast<const char *>(map->data), map->size);
 
         Q_EMIT q->modifiersMap(mods);
     }