usermod/pixels_dice_try: Add missing dep

The "arduino-pixels-dice" library needs the ESP32 BLE subsystem, but
doesn't explicitly depend on it.

usermods/pixels_dice_tray/library.json

@@ -2,6 +2,7 @@
   "name:": "pixels_dice_tray",
   "build": { "libArchive": false},
   "dependencies": {
-    "arduino-pixels-dice":"https://github.com/axlan/arduino-pixels-dice.git"
+    "arduino-pixels-dice":"https://github.com/axlan/arduino-pixels-dice.git",
+    "ESP32 BLE Arduino":"*"
   }
 }