feat: Add ratelimiting to OpWitness API

[stevencartavia]

should close #12871

[mattsse]

these are unrelated, please undo

[stevencartavia]

just the pending_block.rs or also block.rs and transactions.rs?

[mattsse]

good start, we also want to add a new tokio Semaphor for ratelimiting

[stevencartavia]

what would be the number of permits?

and I'm not sure if this is the correct place and way to use it :(

impl<Provider, EvmConfig> OpDebugWitnessApi<Provider, EvmConfig> {
    /// Creates a new instance of the `OpDebugWitnessApi`.
    pub fn new(
        provider: Provider,
        evm_config: EvmConfig,
        task_spawner: Box<dyn TaskSpawner>,
    ) -> Self {
        let builder = OpPayloadBuilder::new(evm_config);
        let semaphore = Arc::new(Semaphore::new(3));
        let inner = OpDebugWitnessApiInner { provider, builder, task_spawner, semaphore };
        Self { inner: Arc::new(inner) }
    }
}

[mattsse]

3 seems fine