Remove old promicro_bootloader_jmp() declarations (#6444)

keyboards/lets_split/sockets/sockets.h

@@ -3,10 +3,8 @@
 
 #include "lets_split.h"
 
-//void promicro_bootloader_jmp(bool program);
 #include "quantum.h"
 
-
 #ifdef USE_I2C
 #include <stddef.h>
 #ifdef __AVR__
@@ -15,8 +13,6 @@
 #endif
 #endif
 
-//void promicro_bootloader_jmp(bool program);
-
 #ifndef FLIP_HALF
 // Standard Keymap
 // (TRRS jack on the left half is to the right, TRRS jack on the right half is to the left)