Fix pico2 extension

Author: tannewt

_board/raspberry_pi_pico2.md

@@ -7,7 +7,7 @@ manufacturer: "Raspberry Pi"
 board_url:
   - "https://www.raspberrypi.com/products/raspberry-pi-pico-2/"
 
-board_image: "raspberry_pi_pico2.png"
+board_image: "raspberry_pi_pico2.jpg"
 date_added: 2024-08-08
 family: raspberrypi
 features: