Remove some useless code from keymaps (#23787)

keyboards/ergodox_ez/util/compile_keymap.py

@@ -431,11 +431,6 @@ def parse_keymaps(config, valid_keycodes):
 #       keymap.c output
 
 USERCODE = """
-// Runs just one time when the keyboard initializes.
-void matrix_init_user(void) {
-
-};
-
 // Runs constantly in the background, in a loop.
 void matrix_scan_user(void) {
     uint8_t layer = get_highest_layer(layer_state);