🩹 Use EXTRUDER_AUTO_FAN_SPEED for _AUTOFAN_SPEED (#23180)

Marlin/src/module/temperature.cpp

       #if BOTH(HAS_FANCHECK, HAS_PWMFANCHECK)
         #define _AUTOFAN_SPEED() fan_check.is_measuring() ? 255 : EXTRUDER_AUTO_FAN_SPEED
       #else
-        #define _AUTOFAN_SPEED() 255
+        #define _AUTOFAN_SPEED() EXTRUDER_AUTO_FAN_SPEED
       #endif
       #define _AUTOFAN_CASE(N) case N: _UPDATE_AUTO_FAN(E##N, fan_on, _AUTOFAN_SPEED()); break