Fix 32-bit crash due to fwretract_settings_t pack(1) (#15333)

Marlin/src/feature/fwretract.h

 
 #include "../inc/MarlinConfigPre.h"
 
-#pragma pack(push, 1) // No padding between fields
-
 typedef struct {
   float retract_length,                     // M207 S - G10 Retract length
         retract_feedrate_mm_s,              // M207 F - G10 Retract feedrate
         swap_retract_recover_feedrate_mm_s; // M208 R - G11 Swap Recover feedrate
 } fwretract_settings_t;
 
-#pragma pack(pop)
-
 #if ENABLED(FWRETRACT)
 
 class FWRetract {