fix: sequencer forwarding

[leovct]

Description

Closes #86

Configure sequencer forwarding to send transactions to the sequencer EL RPC endpoint instead of the CL RPC endpoint.

Nightly workflow: https://github.com/leovct/optimism-package/actions/runs/12199976016

Test

kurtosis run --enclave op --args-file .github/tests/op-geth.yaml .

export ETH_RPC_URL=$(kurtosis port print op op-el-2-op-geth-hildr-op-kurtosis rpc)
curl \
  --request POST \
  --url $ETH_RPC_URL \
  --header 'accept: application/json' \
  --header 'content-type: application/json' \
  --data '{"id":0,"jsonrpc":"2.0","method":"eth_sendRawTransaction","params":["0x02f8718320d5e480018476bb8201825208940000000000000000000000000000000000000000880de0b6b3a764000080c001a09322fe55a0a429fc26fc3703fea0e44298e28ac884afa448f1f9dd0ea6ac080ca07650448283d4afd481d7b690bb5251c75a7aca3a6e41d06cab49b0727218d074"]}'

Without the fix:

{"jsonrpc":"2.0","id":0,"error":{"code":-32601,"message":"the method eth_sendRawTransaction does not exist/is not available"}}

With the fix:

{"jsonrpc":"2.0","id":0,"result":"0x90dc459ccc7429d1cdef3c3e4e7caa069142312b65bfe45cd14b4ff8f6dcd803"}