Remove Optimism feature from chainspec

[mattsse]

Describe the feature

this is closely related to #7679

we should find a way to get rid of optimism specific stuff in chainspec, either by switching to name based hardforks, or a trait abstraction for chainspec.

in the short term, I think using named variants as described in #7679 would be easier and would allow adding additional hardforks and check functions via extension traits

or we go all the way and add trait for chainspec.

Additional context

No response

### Tasks
- [ ] https://github.com/paradigmxyz/reth/issues/10468
- [ ] https://github.com/paradigmxyz/reth/pull/10485
- [ ] https://github.com/paradigmxyz/reth/pull/10482
- [ ] https://github.com/paradigmxyz/reth/issues/10518
- [ ] https://github.com/paradigmxyz/reth/issues/10513
- [ ] https://github.com/paradigmxyz/reth/pull/10944#event-14288349483
- [ ] https://github.com/paradigmxyz/reth/pull/9065
- [ ] https://github.com/paradigmxyz/reth/issues/11238
- [ ] https://github.com/paradigmxyz/reth/issues/11396
- [ ] https://github.com/paradigmxyz/reth/issues/11397