feat: add version_file_path option

Using the same logic as `actions/setup-node`, we can support `asdf`, `volta` or other version management techniques.

test/.tool-versions

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+pnpm 4.11.1

test/package.engines.json

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+{"engines":{"pnpm":"4.11.1"}}

test/package.volta-extends.json

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+{"volta":{"extends":"./package.volta.json"}}

test/package.volta.json

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+{"volta":{"pnpm":"4.11.1"}}