chore: clean up package features

[meyer9]

Make op a toggleable feature instead and ensure that serde and reth-codec flags are enabled where needed.

Depends on paradigmxyz#19005 upstream

[Copilot]

Pull Request Overview

This PR refactors the package feature configuration to make Optimism support toggleable rather than always enabled, improving modularity and reducing dependencies when OP features aren't needed.

• Made op a feature flag that conditionally enables Optimism-related dependencies and features
• Ensured serde and reth-codec features are explicitly enabled where required for proper serialization support
• Added conditional dependency on reth-optimism-primitives only when the op feature is enabled

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[Copilot]

The feature depends on reth-codecs/op but reth-codecs is only listed in [dev-dependencies], not in [dependencies]. This will cause a build error when the op feature is enabled in non-test builds.

[wiz-b4c72f16a4]

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[emhane]

the 'op' feature should actually always be enabled for all optimism crates in order for the InMemorySize implementation to return the correct result. i also opened and issue to move this trait to alloy so that it can be implemented in op-alloy instead of in reth and thereby remove the need for the feature in reth cc @mattsse

[emhane]

we could have a toggle, but then it should be a default feature

[emhane]

likely we have to add the op feature to all the trie crates (or move the InMemorySize trait to alloy cc @mattsse)

[meyer9]

I think we can close this for now