bump blscurve closes #2693 and #2695

[mratsim]

Bump nim-blscurve, closes #2693 #2695

Upstream description: status-im/nim-blscurve#115

[github-actions]

Unit Test Results

     28 files  ±0     328 suites  ±0   1h 8m 30s ⏱️ ±0s
   636 tests ±0     618 ✔️ ±0    18 💤 ±0  0 ❌ ±0 
3 484 runs  ±0  3 380 ✔️ ±0  104 💤 ±0  0 ❌ ±0 

Results for commit 38a5bc8. ± Comparison against base commit 38a5bc8.

♻️ This comment has been updated with latest results.

[arnetheduck]

I'm not sure if we documented it clearly, but we do take some shortcuts crypto.nim - ie the deserialization from database is trusted, so we skip some checks to make startup faster - the thing that might be missing from the docs there might be how and where the preconditions are checked, ie that the publickey doesn't violate some nasty constraint

[mratsim]

We do have a passage there https://github.com/status-im/nimbus-eth2/blob/stable/docs/attestation_flow.md#trustedattestation--trustedindexedattestation