codal_port: Bump micro:bit version to v2.1.0-beta.3

Author: microbit-carlos

src/codal_port/mpconfigport.h

@@ -116,7 +116,7 @@
     { MP_ROM_QSTR(MP_QSTR_open), MP_ROM_PTR(&mp_builtin_open_obj) },
 #endif
 
-#define MICROBIT_RELEASE "2.1.0-beta.2"
+#define MICROBIT_RELEASE "2.1.0-beta.3"
 #define MICROBIT_BOARD_NAME "micro:bit"
 #define MICROPY_HW_BOARD_NAME MICROBIT_BOARD_NAME " v" MICROBIT_RELEASE
 #define MICROPY_HW_MCU_NAME "nRF52833"