Convert Encoder callbacks to be boolean functions (#12805)

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

keyboards/planck/keymaps/grant24/keymap.c

@@ -279,7 +279,7 @@ uint16_t muse_counter = 0;
 uint8_t muse_offset = 70;
 uint16_t muse_tempo = 50;
 
-void encoder_update(bool clockwise) {
+bool encoder_update(bool clockwise) {
   if (muse_mode) {
     if (IS_LAYER_ON(_RAISE)) {
       if (clockwise) {
@@ -309,6 +309,7 @@ void encoder_update(bool clockwise) {
       #endif
     }
   }
+    return true;
 }
 
 void dip_switch_update_user(uint8_t index, bool active) {