Issue #, if available:

Description of changes:

• Fix circular dependencies caused by __version__ stored in __init__.py
• Make known_dynamic_columns, past_dynamic_columns, static_columns explicit properties of the Task instead of automatically inferring them from data.
• Rename target_column -> target to make the name more consistent with str | list[str] typing.
• Rename Task.target_columns_list -> target_columns.

To do

• Update tutorials in docs/
• Handle deprecated field names

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