ci: Reduce executor size

op-e2e: fix TestLargeL1Gaps flake

Revert "[op-node] Add support for non-batched RPC calls when batchSize == 1"

Our CCI usage more than doubled over the last few months. After looking at the config, we were using xlarge VMs for Docker build/publish steps as well as Slither which cost 40 credits/minute. I reduced those to values I think are more appopriate, and reduced some of our Docker instance sizes as well.

op-e2e: Longer seq window for TestSystemMockP2P

op-program: Fix l2 engine API to avoid fetching L2 blocks after the agreed head

op-batcher: Add Channel Bytes Counters

[op-node] Add support for non-batched RPC calls when batchSize == 1

[op-batcher] Bug: panics on nil access

fix(specs/proposals): Sherlock fixes

CI: Increase go lint timeout to 5m

op-program: Fix l2 engine API to avoid fetching L2 blocks after the chain head as part of importing.

op-program: Modify L2 oracle to not return error

op-e2e: Increase TestMockP2P timeout

op-program: Implement oracle based L1 fetcher