Freeze arguments to pick_calculator

[zulissimeta]

Summary of Changes

lru_cache is used to make sure that each MLP calculator is only instantiated once (great!). However, if you want to pass dictionaries through to the underlying calculator (say, config overrides to the fairchem calculator), you will get errors because dictionaries are mutable and lru_cache is unhappy. We can patch this by converting any dictionary kwargs to a frozendict.

Requirements

• My PR is focused on a single feature addition or bugfix.
• My PR has relevant, comprehensive unit tests.
• My PR is on a custom branch (i.e. is not named main).

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[Andrew-S-Rosen]

@zulissimeta: Interesting. Thank you for the PR here.

A question: what is the benefit in using frozendict as opposed to frozenset without requiring an additional dependency? For instance,

d = {"cow": "moo", "cat": "meow"}
d_frozen = frozenset(d.items()) # frozen now!
d_unfrozen = dict(d_frozen) # same as d again!

You would still need a decorator, but I haven't quite figured out yet the value-add for frozendict. If we do need frozendict though, this should be added to pyproject.toml as well.

[Andrew-S-Rosen]

Ah, frozenset will not work on a nested dict like d={"cow": {"moo": 1}}.

While not particularly elegant, I am okay with the proposed approach if there's no other option since frozendict seems reasonably well maintained. Not a huge fan of having another dependency just for this, but I don't know of a better solution. Happy to merge with a pyprojoect.toml update and your approval that it's ready.

[zulissimeta]

Thanks, think it should be good to go now.