refactor: add @zk-kit/artifacts

[sripwoud]

Description

privacy-scaling-explorations/snark-artifacts#45 and privacy-scaling-explorations/zk-kit#288 moved the functions to download the snark artifacts out of @zk-kit/utils and into a dedicated @zk-kit/artifacts package.
This PR adds and uses this package to download the artifacts in the @semaphore-protocol/proof package.

Other information

New release and bumping of @zk-kit/utils here is not necessary. Because the feature removed from it is now brought by @zk-kit/artifacts and this package is now added as a dep in the only semaphore package that uses it: @semaphore-protocol/proof.
Nonetheless once the new release of @zk-kit/utils is released (see privacy-scaling-explorations/zk-kit#290) , we should bump it in @semaphore-protocol/proof too (because now similar functions could theoretically imported from 2 different packages...): captured in #789

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation NA
• My changes generate no new warnings
• I have run yarn format and yarn lint without getting any errors
• I have added tests that prove my fix is effective or that my feature works NA
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[sripwoud]

setting back to draft although the checks pass.

there is a remaining bug related to jest picking the browser exports instead of node.

I am not sure why (especially because jest's default testEnvironment is node)

But it causes the circuits and contracts tests to fail locally (and they are skipped in the ci).

[cedoor]

setting back to draft although the checks pass.

there is a remaining bug related to jest picking the browser exports instead of node.

I am not sure why (especially because jest's default testEnvironment is node)

But it causes the circuits and contracts tests to fail locally (and they are skipped in the ci).

This privacy-scaling-explorations/snark-artifacts#57 should fix it. I tested it locally.

[vplasencia]

Yes, that new config works. Then I think this: https://github.com/semaphore-protocol/semaphore/pull/788/files#diff-860bd1f15d1e0bafcfc6f62560524f588e6d6bf56d4ab1b0f6f8146461558730R16

can be removed.

[sripwoud]

Thanks @cedoor @vplasencia
yes all tests pass locally now