anemoi-plugins does not add any dependencies

[bdvllrs]

Describe the bug
anemoi-plugins does not add any dependencies

To Reproduce
Steps to reproduce the behavior:

• anemoi-plugins new datasets.create.source --name foo
• there is no dependencies field in pyproject.toml but the create file require anemoi-datasets and earthkit-data.

[passionworkeer]

This is a common issue with template generators. The CLI command uses packages that aren't declared as dependencies in pyproject.toml.

To fix this:

1. Check the template file that generates pyproject.toml (usually in a templates/ or cookiecutter directory)
2. Add the required dependencies to the template: anemoi-datasets and earthkit-data
3. Consider using dynamic dependencies based on the command flags - for example, only add anemoi-datasets if the create command is used

You can look at how similar projects like cookiecutter-pypackage handle conditional dependencies.