Remove empty action_function()

tests/basic/keymap.c

@@ -41,6 +41,3 @@ const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt) {
     }
     return MACRO_NONE;
 };
-
-void action_function(keyrecord_t *record, uint8_t id, uint8_t opt) {
-}