Serialization: support saving torch state dict to disk (#2314)
* Save Pytorch state dict
* fix tests
* fix test
* Add tests
* docstring
* docs
* Skip if torch not installed
* Respect custom filename pattern
* Update docs/source/en/package_reference/serialization.md
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>
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Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>