Option to ignore SD at startup (#20099)

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

Marlin/src/sd/cardreader.cpp

@@ -425,7 +425,8 @@ void CardReader::manage_media() {
 
     if (stat) {                       // Media Inserted
       safe_delay(500);                // Some boards need a delay to get settled
-      mount();                        // Try to mount the media
+      if (TERN1(SD_IGNORE_AT_STARTUP, old_stat != 2))
+        mount();                      // Try to mount the media
       #if MB(FYSETC_CHEETAH, FYSETC_CHEETAH_V12, FYSETC_AIO_II)
         reset_stepper_drivers();      // Workaround for Cheetah bug
       #endif