pybricks.tools.run_task: call MICROPY_VM_HOOK_LOOP

Since removing the gc_collect() from the run_task() loop, when setting
loop_time_ms to 0, it was possible that the contiki events were never
getting handled, causing random crashes due to watchdog timeout or
UART device failure.

This adds MICROPY_VM_HOOK_LOOP in the loop to ensure that background
events are always being handled even when running in a tight loop.

Fixes: 5a0c7d5 ("pybricks/tools/pb_module_tools: remove gc_collect() from run loop")

pybricks/tools/pb_module_tools.c

@@ -238,6 +238,7 @@ static mp_obj_t pb_module_tools_run_task(size_t n_args, const mp_obj_t *pos_args
     if (nlr_push(&nlr) == 0) {
 
         while (mp_iternext(iterable) != MP_OBJ_STOP_ITERATION) {
+            MICROPY_VM_HOOK_LOOP
 
             if (loop_time == 0) {
                 continue;