Pyxel fails on Raspberry Pi 4
Good afternoon.

I'm testing my projects on my Raspberry Pi 4 with aarch64, but when I run `pyxel run game.py` I get this error:

```sh
Traceback (most recent call last):
  File "/home/pi/ticoban/venv/bin/pyxel", line 8, in <module>
    sys.exit(cli())
  File "/home/pi/ticoban/venv/lib/python3.9/site-packages/pyxel/cli.py", line 62, in cli
    command[1](*sys.argv[2:])
  File "/home/pi/ticoban/venv/lib/python3.9/site-packages/pyxel/cli.py", line 178, in run_python_script
    runpy.run_path(python_script_file, run_name="__main__")
  File "/usr/lib/python3.9/runpy.py", line 268, in run_path
    return _run_module_code(code, init_globals, run_name,
  File "/usr/lib/python3.9/runpy.py", line 97, in _run_module_code
    _run_code(code, mod_globals, init_globals,
  File "/usr/lib/python3.9/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "ticoban.py", line 2, in <module>
    from rock import Rock
ModuleNotFoundError: No module named 'rock'
```

I tried to install the requested module, but I get another error, `ImportError: cannot import name 'Rock' from 'rock' (/home/pi/ticoban/venv/lib/python3.9/site-packages/rock/__init__.py)`.

I've been looking, but I can't find a solution, and I don't see that Pyxel depends on such a module.

Does anyone know how to fix it? Thanks in advance
