Update pins_FORMBOT_TREX3.h (#13058)

Marlin/src/pins/pins_FORMBOT_TREX3.h

 #define FAN1_PIN           12
 
 #define NUM_RUNOUT_SENSORS  2
-#define FIL_RUNOUT_PIN     23
+#define FIL_RUNOUT_PIN     22
 #define FIL_RUNOUT2_PIN    21
 
 //