Remove unneeded permute from Poseidon hashing

[ecmargo]

Description

Previously, the implementation of Poseidon permuted on every absorb, and only a subset of the squeezes. This resulted in 2x the number of constraints in comparison to the Neptune implementation.

The Neptune implementation permutes on absorb only when the absorb position is equivalent to the rate. And it instead permutes on every squeeze after an absorb and when the position is equivalent to the rate.

After speaking with @Pratyush, modified the arkworks sponge to have the same permutation pattern.

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• Targeted PR against correct branch (main)
• Linked to Github issue with discussion and accepted design OR have an explanation in the PR that describes this work.
• Wrote unit tests
• Updated relevant documentation in the code
• Added a relevant changelog entry to the Pending section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer