Remove the pasta fork

[huitseeker]

Anyone that imports Arecibo (and Lurk) needs to include the following lines:

[patch.crates-io]
pasta_curves = { git = "https://github.com/lurk-lab/pasta_curves", branch = "dev" }

These lines are needed because both {Lurk, Arecibo} x { halo2curves } use pasta_curves, and more importantly traits defined in pasta_curves (because zkcrypto/group#48 is not resolved). Yet {Arecibo, Lurk} is using a fork of pasta_curves, whereas halo2curves isn't, so they disagree on the definition of those traits. This is solved for Arecibo by adding a patch stanza here:
https://github.com/lurk-lab/arecibo/blob/5bdc0ee4b2434dd998679b8e36b5b0b6d2588019/Cargo.toml#L120-L122
But that's not transitive, so it has to be reproduced here in lurk :
https://github.com/lurk-lab/lurk-rs/blob/f2d70f4f7c295cde6f07ae391f601a0d49c3965e/Cargo.toml#L189-L191
... and so it goes for any downstream dependency.

The reason we use a pasta_curves fork is that to implement something like microsoft/Nova#179, we needed uncompressed point encoding to be actually implemented for the curves in question, and that's not the case for pasta_curves ( zcash/pasta_curves#73 is still opened and unreviewed ). Hence a fork.

The real solution for us at this stage, since we mostly depend on bn254/grumpkin, is to move out of pasta_curves. We should:

1. excise the fork from our dependency suite,
2. rebase [Do not merge until Git dependencies removed] Uncompressed Encoding for Affine Points microsoft/Nova#179 on arecibo, which can actually use it on bn254/grumpkin (for which uncompressed encodings are available),
3. This would probably close [Zeromorph] Avoid decompressing G2 points #91