Init (stow) BLTouch before X/Y homing (#21192)

Marlin/src/gcode/calibrate/G28.cpp

       // Raise Z before homing any other axes and z is not already high enough (never lower z)
       if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("Raise Z (before homing) by ", z_homing_height);
       do_z_clearance(z_homing_height);
+      TERN_(BLTOUCH, bltouch.init());
     }
 
     #if ENABLED(QUICK_HOME)
           stepper.set_separate_multi_axis(false);
         #endif
 
-        TERN_(BLTOUCH, bltouch.init());
         TERN(Z_SAFE_HOMING, home_z_safely(), homeaxis(Z_AXIS));
         probe.move_z_after_homing();
       }