change(core): Updated at core version to 3258eeea

- fix(wifi): Fixed AT+CWMODE=1,1 sometimes failed to trigger wifi reconnection
- fix(ESPAT-2382): Fixed a connection index duplicated issue (nimble)
- fix(ESPAT-2402): Fixed a potential crash caused by custom gatts service table (nimble)
- fix(ESPAT-2486): Fixed an issue where passthrough data could not be sent using characteristics with the notify property (nimble)
- fix(ESPAT-2490): Formatted the indication message for scan completion (nimble)
- fix(ESPAT-2491): Added a mechanism to control the maximum number of connections (nimble)

Author: ustccw

components/at/lib/VERSION

@@ -1,7 +1,7 @@
-ESP32:   d845736
-ESP32C3: d845736
-ESP32C2: d845736
-ESP32C5: d845736
-ESP32C6: d845736
-ESP32C61:d845736
-ESP32S2: d845736
+ESP32:   3258eee
+ESP32C3: 3258eee
+ESP32C2: 3258eee
+ESP32C5: 3258eee
+ESP32C6: 3258eee
+ESP32C61:3258eee
+ESP32S2: 3258eee