Add core/fallback encoder behaviour (#20320)

keyboards/handwired/swiftrax/bumblebee/bumblebee.c

@@ -16,17 +16,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 #include "bumblebee.h"
 
-// Encoder
-bool encoder_update_kb(uint8_t index, bool clockwise) {
-    if (!encoder_update_user(index, clockwise))
-        return false;
-    if (clockwise)
-        tap_code(KC_VOLU);
-    else
-        tap_code(KC_VOLD);
-    return true;
-}
-
 // Initialize all RGB indicators to 'off'
 void keyboard_post_init_kb(void) {
     rgblight_setrgb_at(0, 0, 0, 0); // [..., 0] = top LED