Fix matrix_scan_user is not called at stm32 env(projectkb/alice etc..) which using cannonkeys/stm32f072 (#7821)

keyboards/cannonkeys/stm32f072/keyboard.c

@@ -74,6 +74,7 @@ void matrix_scan_kb(void)
   #ifdef RGBLIGHT_ENABLE
     rgblight_task();
   #endif
+    matrix_scan_user();
 }
 
 bool process_record_kb(uint16_t keycode, keyrecord_t *record) {
@@ -175,4 +176,4 @@ void via_eeprom_reset(void)
     eeconfig_disable();
 }
 
-#endif // VIA_ENABLE
+#endif // VIA_ENABLE