chore(deps): remove dependency on `ethereum-execution`

[danceratopz]

In order for ethereum/execution-specs to use execution-spec-tests as a package we need to remove the dependency on Frontier accounts that are imported from execution-specs, otherwise there will be a circular dependency.

[felix314159]

To provide more context:

src/pytest_plugins/execute/rpc/hive.py:13:from ethereum.crypto.hash import keccak256
src/ethereum_test_types/account_types.py:7:from ethereum.frontier.fork_types import Account as FrontierAccount
src/ethereum_test_types/account_types.py:8:from ethereum.frontier.fork_types import Address as FrontierAddress
src/ethereum_test_types/account_types.py:9:from ethereum.frontier.state import State, set_account, set_storage, state_root

And also the keccak256 dependency, eels just uses pycryptodome's Crypto.Hash we can easily do this ourselves