op-reth: Remove patch section and reth inter-dependencies on optimism crates

Summary

Once op-reth is migrated to the monorepo:

The op-reth/Cargo.toml workspace currently requires a [patch] section to override reth's internal dependencies on optimism crates. This is needed because some reth crates have optional dependencies on reth-optimism-* crates behind the op feature flag.

Problem

When using reth as a git dependency (tag v1.10.2), the following reth crates pull in their own versions of optimism crates:

This creates duplicate crate instances (local vs git-sourced) with incompatible trait implementations.

Current Workaround

[patch."https://github.com/paradigmxyz/reth"]
reth-optimism-chainspec = { path = "chainspec/" }
reth-optimism-primitives = { path = "primitives/" }

Proposed Solution

Work with the reth team to either:

1. Remove the optional optimism dependencies from core reth crates
2. Or establish a proper separation where op-reth can be used without patch overrides

This would allow op-reth to be a clean standalone workspace without needing to patch upstream dependencies.

Start with op-reth/Cargo.toml and inspect the [patch] entries for reth-optimism-chainspec and reth-optimism-primitives, along with the op feature dependencies listed in the issue. Coordinate with the reth team on the upstream separation; done means op-reth no longer needs patch overrides and does not pull duplicate optimism crate instances.