Fix SD pins for SKR Pro and GTR (#19047)

Marlin/src/sd/cardreader.cpp

@@ -137,6 +137,10 @@ CardReader::CardReader() {
   // Disable autostart until card is initialized
   autostart_index = -1;
 
+  #if ENABLED(SDSUPPORT) && PIN_EXISTS(SD_DETECT)
+    SET_INPUT_PULLUP(SD_DETECT_PIN);
+  #endif
+  
   #if PIN_EXISTS(SDPOWER)
     OUT_WRITE(SDPOWER_PIN, HIGH); // Power the SD reader
   #endif