Replace SubmitBlockRequest with alloy's SubmitBlockRequest

[mattsse]

rbuilder/crates/rbuilder/src/mev_boost/submission.rs

Lines 28 to 34 in 9a4f6b6

	#[derive(Debug, Clone, Serialize, Deserialize)]
	#[serde(untagged)]
	pub enum SubmitBlockRequest {
	Capella(CapellaSubmitBlockRequest),
	Deneb(DenebSubmitBlockRequest),
	Electra(ElectraSubmitBlockRequest),
	}

I just upstreamed this to alloy: alloy-rs/alloy#2391 in 0.15.9

this could be replaced

[faheelsattar]

hey can i pick this?