Parameterize weights_only during load to allow loading of unusual models

[markscsmith]

When using stable_baselines3, it is possible to specify a learning_rate_schedule that is a function rather than a static number. If this function contains numpy scalars (e.g.: np.pi) these scalars will cause the model to fail to load with weights_only=True because the numpy scalars are not a supported type.

Description

The primary change is a "weights_only" parameter for the load function, allowing the user to change the weights_only parameter as needed when loading models of this type.

Motivation and Context

This is to address an edge case around learning_rate_schedule being a function and also using data types that are not marked safe as part of torch.load

Related to enhancement #1852

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[markscsmith]

I wasn't sure if this should be a new issue since I referenced the existing one, but if you'd prefer I open that instead of using the existing enhancement I'm happy to do that instead! Thanks again!

[markscsmith]

Opening different PR with from branch to allow choice of feature to be merged