The [kilic](https://github.com/kilic/bls12-381) bls12381 implementation
has been archived. It shouldn't be necessary to include it as a fuzzing
target any longer.
This also adds fuzzers for G1/G2 mul that use inputs that are guaranteed
to be valid. Previously, we just did random input fuzzing for these
precompiles.
This PR updates the bls contracts from our internal implementation which is an unmaintained fork of the kilic library to the gnark-crypto library that is actively maintained by consensys.
It also updates the gas-costs according to the EIP