Bump secp256k1 in /solidity

Bumps  and [secp256k1](https://github.com/cryptocoinjs/secp256k1-node). These dependencies needed to be updated together.

Updates `secp256k1` from 4.0.2 to 4.0.4
- [Release notes](https://github.com/cryptocoinjs/secp256k1-node/releases)
- [Commits](cryptocoinjs/secp256k1-node@v4.0.2...v4.0.4)

Updates `secp256k1` from 3.8.0 to 4.0.4
- [Release notes](https://github.com/cryptocoinjs/secp256k1-node/releases)
- [Commits](cryptocoinjs/secp256k1-node@v4.0.2...v4.0.4)

---
updated-dependencies:
- dependency-name: secp256k1
  dependency-type: indirect
- dependency-name: secp256k1
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>