Constify Qt containers passed to ranges

This constifies a few mutable Qt containers passed to std::ranges to improve the efficiency.

src/backends/libinput/connection.cpp

@@ -287,10 +287,10 @@ void Connection::processEvents()
             break;
         }
         case LIBINPUT_EVENT_DEVICE_REMOVED: {
-            auto it = std::ranges::find_if(m_devices, [&event](Device *d) {
+            auto it = std::ranges::find_if(std::as_const(m_devices), [&event](Device *d) {
                 return event->device() == d;
             });
-            if (it == m_devices.end()) {
+            if (it == m_devices.cend()) {
                 // we don't know this device
                 break;
             }

src/backends/x11/windowed/x11_windowed_backend.cpp

@@ -513,10 +513,10 @@ void X11WindowedBackend::updateWindowTitle()
 
 void X11WindowedBackend::handleClientMessage(xcb_client_message_event_t *event)
 {
-    auto it = std::ranges::find_if(m_outputs, [event](X11WindowedOutput *output) {
+    auto it = std::ranges::find_if(std::as_const(m_outputs), [event](X11WindowedOutput *output) {
         return output->window() == event->window;
     });
-    if (it == m_outputs.end()) {
+    if (it == m_outputs.cend()) {
         return;
     }
     if (event->type == m_protocols && m_protocols != XCB_ATOM_NONE) {