Upgrade to Torch 2.x and Lightning 2.x

⬆️ Upgrade ⬆️

Changes documented in #682 :

• Remove the optimizer_idx in lr_scheduler_step in System.
• Replace torch.symeigh by torch.linalg.eigh in beamforming.py
• Disable X-UMX as it uses torch1.x STFT : @r-sawata do you want to fix it ?
• Replace on_*_end with on_training_*_end
• Replace torch.testing.assert_allclose with torch.testing.assert_close.

Happy coding 🙃