[bugfix]: Fix type hint errors in Features.py (#5556)

* [bugfix]: Fix type hint errors

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* [revert]: Use '|' instead of Union

* [revert]: undo some unwanted changes

* Fix pre-commit errors

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Co-authored-by: huibosa_macmini <huibosa@email.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Hailin Wang <hailin.wang@connect.polyu.hk>