docs(wokwi-pi-pico): remove the ArduinoCore-mbed core

We now always compile with the Arduino-Pico core

Author: urish

docs/parts/wokwi-pi-pico.md

@@ -74,28 +74,9 @@ Legend:
 
 The Arduino core provides the built-in Arduino functions, such as `pinMode()` and `digitalRead()`, as well as a set of standard Arduino libraries, such as Servo, Wire and SPI.
 
-When compiling your code for the Raspberry Pi Pico, you can choose between two different cores:
+When compiling your code for the Raspberry Pi Pico and for the Raspberry Pi Pico W, Wokwi uses the [Arduino-Pico core](https://github.com/earlephilhower/arduino-pico), built on top of [the Pi Pico SDK](https://github.com/raspberrypi/pico-sdk).
 
-- The [official Pi Pico core](https://github.com/arduino/ArduinoCore-mbed), based on Mbed OS. This is the default.
-- [The community maintained Pi Pico Arduino Core](https://github.com/earlephilhower/arduino-pico), built on top of [the Pi Pico SDK](https://github.com/raspberrypi/pico-sdk).
-
-You can learn about the key differences between these two cores in [this GitHub comment](https://github.com/earlephilhower/arduino-pico/issues/117#issuecomment-830356795).
-
-To select a core, set the "env" attribute of the `wokwi-pi-pico` part. For the official Arduino core, use the value "arduino-core". For the community maintained core, set "env" to "arduino-community". e.g.:
-
-```json
-  "parts": [
-    {
-      "type": "wokwi-pi-pico",
-      "id": "pico",
-      "attrs": {
-        "env": "arduino-community"
-      }
-      …
-    },
-    …
-  ]
-```
+In the past, Wokwi also supported the [RP2040-mbed Arduino core](https://github.com/arduino/ArduinoCore-mbed), but it has been deprecated in favor of the Arduino-Pico core.
 
 ### Serial Monitor