feat(core): Updated at core version to 406e4081

- fix(ESPAT-2169): Fixed a ble connection timeout issue
- fix(ESPAT-2168): Fixed a ble scan stop abnormally issue
- fix(ESPAT-2298): Fixed a ble send indication and write fail issue
- fix(ESPAT-2303): Removed redundant print information

Author: ustccw

components/at/lib/VERSION

@@ -1,4 +1,4 @@
 ESP32:   f33f3c8
 ESP32C3: 3b13d04
-ESP32C2: af0930d
+ESP32C2: 406e408
 ESP32C6: f33f3c8