🐛 Fix redundant heater / sensor pin assignments (#22309)

Marlin/src/pins/linux/pins_RAMPS_LINUX.h

@@ -192,7 +192,7 @@
 #else                                             // Non-specific are "EFB" (i.e., "EFBF" or "EFBE")
   #define FAN_PIN                   RAMPS_D9_PIN
   #define HEATER_BED_PIN            RAMPS_D8_PIN
-  #if HOTENDS == 1
+  #if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
     #define FAN1_PIN                MOSFET_D_PIN
   #else
     #define HEATER_1_PIN            MOSFET_D_PIN

Marlin/src/pins/lpc1768/pins_BTT_SKR_common.h

@@ -65,7 +65,7 @@
   #define TEMP_BED_PIN                  P0_23_A0  // A0 (T0) - (67) - TEMP_BED_PIN
 #endif
 
-#if HOTENDS == 1
+#if HOTENDS == 1 && TEMP_SENSOR_REDUNDANT_SOURCE != 1
   #if TEMP_SENSOR_PROBE
     #define TEMP_PROBE_PIN            TEMP_1_PIN
   #elif TEMP_SENSOR_CHAMBER
@@ -92,7 +92,7 @@
 #ifndef HEATER_0_PIN
   #define HEATER_0_PIN                     P2_07
 #endif
-#if HOTENDS == 1
+#if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
   #ifndef FAN1_PIN
     #define FAN1_PIN                       P2_04
   #endif

Marlin/src/pins/lpc1768/pins_MKS_SGEN_L.h

@@ -202,7 +202,7 @@
 //
 #define HEATER_BED_PIN                     P2_05
 #define HEATER_0_PIN                       P2_07
-#if HOTENDS == 1
+#if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
   #ifndef FAN1_PIN
     #define FAN1_PIN                       P2_06
   #endif

Marlin/src/pins/lpc1768/pins_RAMPS_RE_ARM.h

@@ -217,7 +217,7 @@
   #define FAN1_PIN                  RAMPS_D8_PIN
 #elif DISABLED(IS_RAMPS_SF)                       // Not Spindle, Fan (i.e., "EFBF" or "EFBE")
   #define HEATER_BED_PIN            RAMPS_D8_PIN
-  #if HOTENDS == 1
+  #if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
     #define FAN1_PIN                MOSFET_D_PIN
   #else
     #define HEATER_1_PIN            MOSFET_D_PIN

Marlin/src/pins/ramps/pins_RAMPS.h

@@ -219,7 +219,7 @@
   #define FAN1_PIN                  RAMPS_D8_PIN
 #elif DISABLED(IS_RAMPS_SF)                       // Not Spindle, Fan (i.e., "EFBF" or "EFBE")
   #define HEATER_BED_PIN            RAMPS_D8_PIN
-  #if HOTENDS == 1
+  #if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
     #define FAN1_PIN                MOSFET_D_PIN
   #else
     #define HEATER_1_PIN            MOSFET_D_PIN

Marlin/src/pins/stm32f1/pins_MKS_ROBIN_NANO.h

@@ -105,7 +105,7 @@
 #ifndef HEATER_0_PIN
   #define HEATER_0_PIN                      PC3
 #endif
-#if HOTENDS == 1
+#if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
   #ifndef FAN1_PIN
     #define FAN1_PIN                        PB0
   #endif

Marlin/src/pins/stm32f4/pins_BTT_SKR_V2_0_common.h

@@ -210,7 +210,7 @@
 #define TEMP_0_PIN                          PA2   // TH0
 #define TEMP_1_PIN                          PA3   // TH1
 
-#if HOTENDS == 1
+#if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
   #if TEMP_SENSOR_PROBE
     #define TEMP_PROBE_PIN            TEMP_1_PIN
   #elif TEMP_SENSOR_CHAMBER