chore: deprecate hash_constraint_system and checksum_constraint_system

[TomAFrench]

chore: deprecate

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Description

Summary of changes

It's not clear to me what benefit having these functions in ACVM gives as we currently don't use either of them and by having these two functions we're being opinionated about which hash functions to use whereas users may want to use others.

If we want to add some knowledge about hashing ACIR then I'd say that we should just implement Hash on the Circuit struct and leave it at that.

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Test additions / changes

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Checklist

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt with default settings.
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Additional context

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[kevaundray]

The idea was so that multiple frontends would not need to maybe wrongly implement hash on their circuit, ie by using md5 which may not be secure for their usecase.

I can see the argument for removing them as it's somewhat out of scope for acvm