Merge pull request #7530 from GMagician/Code-reduction

Code reduction with some configurations

Marlin/Marlin_main.cpp

     setup_endstop_interrupts();
   #endif
 
-  #if ENABLED(SWITCHING_EXTRUDER)
+  #if ENABLED(SWITCHING_EXTRUDER) && !DONT_SWITCH
     move_extruder_servo(0);  // Initialize extruder servo
   #endif