Remove empty override functions (#14312)

* Remove empty override functions, 0-9

* Remove empty override functions, A-D

* Remove empty override functions, E-H

* Remove empty override functions, handwired

* Remove empty override functions, I-L

* Remove empty override functions, M-P

* Remove empty override functions, Q-T

* Remove empty override functions, U-Z

keyboards/spacetime/keymaps/default/keymap.c

@@ -67,19 +67,3 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 layer_state_t layer_state_set_user(layer_state_t state) {
   return update_tri_layer_state(state, _LOWER, _RAISE, _ADJUST);
 }
-
-bool process_record_user(uint16_t keycode, keyrecord_t *record) {
-  return true;
-}
-
-void matrix_init_user(void) {
-
-}
-
-void matrix_scan_user(void) {
-
-}
-
-void led_set_user(uint8_t usb_led) {
-
-}