Prevent extra settings.load on boot (#14499)

Marlin/src/Marlin.cpp

@@ -941,7 +941,7 @@ void setup() {
 
   // Load data from EEPROM if available (or use defaults)
   // This also updates variables in the planner, elsewhere
-  (void)settings.load();
+  settings.first_load();
 
   #if HAS_M206_COMMAND
     // Initialize current position based on home_offset

Marlin/src/module/configuration_store.h

@@ -29,8 +29,6 @@
 
 class MarlinSettings {
   public:
-    MarlinSettings() { }
-
     static uint16_t datasize();
 
     static void reset();
@@ -55,9 +53,15 @@ class MarlinSettings {
     #endif
 
     #if ENABLED(EEPROM_SETTINGS)
+
       static bool load();      // Return 'true' if data was loaded ok
       static bool validate();  // Return 'true' if EEPROM data is ok
 
+      static inline void first_load() {
+        static bool loaded = false;
+        if (!loaded && load()) loaded = true;
+      }
+
       #if ENABLED(AUTO_BED_LEVELING_UBL) // Eventually make these available if any leveling system
                                          // That can store is enabled
         static uint16_t meshes_start_index();
@@ -73,6 +77,8 @@ class MarlinSettings {
     #else
       FORCE_INLINE
       static bool load() { reset(); report(); return true; }
+      FORCE_INLINE
+      static void first_load() { (void)load(); }
     #endif
 
     #if DISABLED(DISABLE_M503)

Marlin/src/sd/cardreader.cpp

@@ -353,8 +353,8 @@ void CardReader::initsd() {
   else {
     flag.detected = true;
     SERIAL_ECHO_MSG(MSG_SD_CARD_OK);
-    #if ENABLED(EEPROM_SETTINGS) && DISABLED(FLASH_EEPROM_EMULATION)
-      (void)settings.load();
+    #if ENABLED(EEPROM_SETTINGS) && NONE(FLASH_EEPROM_EMULATION, SPI_EEPROM, I2C_EEPROM)
+      settings.first_load();
     #endif
   }
   setroot();
@@ -560,10 +560,8 @@ void CardReader::checkautostart() {
   if (autostart_index < 0 || flag.sdprinting) return;
 
   if (!isDetected()) initsd();
-
-  #if ENABLED(EEPROM_SETTINGS) && DISABLED(FLASH_EEPROM_EMULATION)
-    SERIAL_ECHOLNPGM("Loading settings from SD");
-    (void)settings.load();
+  #if ENABLED(EEPROM_SETTINGS) && NONE(FLASH_EEPROM_EMULATION, SPI_EEPROM, I2C_EEPROM)
+    else settings.first_load();
   #endif
 
   if (isDetected()