Fix compile-time PWM_PIN (#18793)

Co-authored-by: Scott Lahteine <github@thinkyhead.com>

Marlin/src/inc/SanityCheck.h

 #endif
 #undef _RGB_TEST
 
+#if DISABLED(NO_COMPILE_TIME_PWM)
+  #define _TEST_PWM(P) PWM_PIN(P)
+#else
+  #define _TEST_PWM(P) 1 // pass
+#endif
+
 /**
  * Auto Fan check for PWM pins
  */
-#if HAS_AUTO_FAN && EXTRUDER_AUTO_FAN_SPEED != 255 && DISABLED(NO_COMPILE_TIME_PWM)
+#if HAS_AUTO_FAN && EXTRUDER_AUTO_FAN_SPEED != 255
   #define AF_ERR_SUFF "_AUTO_FAN_PIN is not a PWM pin. Set EXTRUDER_AUTO_FAN_SPEED to 255."
   #if HAS_AUTO_FAN_0
-    static_assert(PWM_PIN(E0_AUTO_FAN_PIN), "E0" AF_ERR_SUFF);
+    static_assert(_TEST_PWM(E0_AUTO_FAN_PIN), "E0" AF_ERR_SUFF);
   #elif HAS_AUTO_FAN_1
-    static_assert(PWM_PIN(E1_AUTO_FAN_PIN), "E1" AF_ERR_SUFF);
+    static_assert(_TEST_PWM(E1_AUTO_FAN_PIN), "E1" AF_ERR_SUFF);
   #elif HAS_AUTO_FAN_2
-    static_assert(PWM_PIN(E2_AUTO_FAN_PIN), "E2" AF_ERR_SUFF);
+    static_assert(_TEST_PWM(E2_AUTO_FAN_PIN), "E2" AF_ERR_SUFF);
   #elif HAS_AUTO_FAN_3
-    static_assert(PWM_PIN(E3_AUTO_FAN_PIN), "E3" AF_ERR_SUFF);
+    static_assert(_TEST_PWM(E3_AUTO_FAN_PIN), "E3" AF_ERR_SUFF);
   #elif HAS_AUTO_FAN_4
-    static_assert(PWM_PIN(E4_AUTO_FAN_PIN), "E4" AF_ERR_SUFF);
+    static_assert(_TEST_PWM(E4_AUTO_FAN_PIN), "E4" AF_ERR_SUFF);
   #elif HAS_AUTO_FAN_5
-    static_assert(PWM_PIN(E5_AUTO_FAN_PIN), "E5" AF_ERR_SUFF);
+    static_assert(_TEST_PWM(E5_AUTO_FAN_PIN), "E5" AF_ERR_SUFF);
   #elif HAS_AUTO_FAN_6
-    static_assert(PWM_PIN(E6_AUTO_FAN_PIN), "E6" AF_ERR_SUFF);
+    static_assert(_TEST_PWM(E6_AUTO_FAN_PIN), "E6" AF_ERR_SUFF);
   #elif HAS_AUTO_FAN_7
-    static_assert(PWM_PIN(E7_AUTO_FAN_PIN), "E7" AF_ERR_SUFF);
+    static_assert(_TEST_PWM(E7_AUTO_FAN_PIN), "E7" AF_ERR_SUFF);
   #endif
 #endif
 
   #elif ENABLED(SPINDLE_LASER_PWM)
     #if !defined(SPINDLE_LASER_PWM_PIN) || SPINDLE_LASER_PWM_PIN < 0
       #error "SPINDLE_LASER_PWM_PIN is required for SPINDLE_LASER_PWM."
-    #elif !PWM_PIN(SPINDLE_LASER_PWM_PIN)
+    #elif !_TEST_PWM(SPINDLE_LASER_PWM_PIN)
       #error "SPINDLE_LASER_PWM_PIN not assigned to a PWM pin."
     #elif !defined(SPINDLE_LASER_PWM_INVERT)
       #error "SPINDLE_LASER_PWM_INVERT is required for (SPINDLE|LASER)_FEATURE."
     #error "DIRECT_STEPPING is incompatible with LIN_ADVANCE. Enable in external planner if possible."
   #endif
 #endif
+
+// Misc. Cleanup
+#undef _TEST_PWM