Remove `openvm_v13` post-Galileo

We currently maintain a `ProverConfig` field `openvm_v13` to denote whether or not the EVM proof generation depends on OpenVM@v1.3.

The difference between v1.3 and v1.4.1 is that v1.4.1 uses `k=23` a the degree for the Halo2 parameters, instead of `k=24` in v1.3.

After Galileo is live on mainnet, we do not need to maintain this support and should be removed.