The previous implementation in darts.darts.models.forecasting.tcn_mode was using `torch.nn.utils.weight_norm`, which is deprecated in favor of `torch.nn.utils.parametrizations.weight_norm`. This commit replaces two occurrences of `torch.nn.utils.weight_norm` with the recommended `torch.nn.utils.parametrizations.weight_norm` to resolve the deprecation warning.

Corrected file saving process for checkpoint files (ckpt) to filter out occurrences of the string '.pt' from the previous file path."