Make default layer size 16-bit (#15286)

Co-authored-by: James Young <18669334+noroadsleft@users.noreply.github.com>

keyboards/kbdfans/kbd75/keymaps/edulpn/keymap.c

@@ -45,7 +45,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 };
 
 layer_state_t layer_state_set_user(layer_state_t state) {
-    switch (biton32(state)) {
+    switch (get_highest_layer(state)) {
     case WINDOWS_LAYER:
         rgblight_setrgb_blue();
         break;