Drop support for abandoned Briki boards

Author: ivankravets

.github/workflows/examples.yml

@@ -11,7 +11,6 @@ jobs:
         example:
           - "examples/arduino-ble5-advertising"
           - "examples/arduino-blink"
-          - "examples/arduino-briki-internal-libs"
           - "examples/arduino-usb-keyboard"
           - "examples/arduino-wifiscan"
           - "examples/espidf-arduino-blink"