Expose `weights_only` argument for loading checkpoints in `Fabric.load()` and `Fabric.load_raw()` (#21470)

* Expose weights_only in Fabric.load

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* Extend Fabric.load docstring with weights_only argument

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* Revert "Merge branch 'fabric-load-weights-only' of https://github.com/CodeVishal-17/pytorch-lightning into fabric-load-weights-only"

This reverts commit 6143e653e4b64cbdbc2e95f57d61394b39ad3773, reversing
changes made to debde18e0771006c4151b990853e7165265dfbad.

* Update fabric.py

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* add tests

* add chlog

* add weights_only option to load_raw method for checkpoint loading

* add docs for weights_only parameter to Strategy class for checkpoint loading

* update docsstrings

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Bhimraj Yadav <[email protected]>