refactor(freertos/idf): Move weak xTimerCreateTimerTask() to IDF additions header

A weak xTimerCreateTimerTask() was added to tasks.c as a workaround in ESP-IDF
in order to prevent timers.c from being linked when unused.

This commit moves that workaround to `freertos_tasks_c_additions.h`

components/freertos/FreeRTOS-Kernel/tasks.c

@@ -6304,9 +6304,3 @@ static void prvAddCurrentTaskToDelayedList( TickType_t xTicksToWait,
     #endif
 
 #endif /* if ( configINCLUDE_FREERTOS_TASK_C_ADDITIONS_H == 1 ) */
-
-/* If timers.c is not referenced anywhere, don't create the timer task to save RAM */
-BaseType_t __attribute__( ( weak ) ) xTimerCreateTimerTask( void )
-{
-    return pdPASS;
-}