feat: use alloy SubmitBlockRequest

[varun-doshi]

📝 Summary

Use SubmitBlockRequest from alloy

💡 Motivation and Context

Fixes #611

✅ I have completed the following steps:

• Run make lint
• Run make test
• Added tests (if applicable)

[Copilot]

Pull Request Overview

This PR replaces the local SubmitBlockRequest type with the upstream SubmitBlockRequest from alloy_rpc_types_beacon, updating imports, client logic, and tests to use the external definition.

• Import and consume alloy_rpc_types_beacon::relay::SubmitBlockRequest across crates
• Remove the older local SubmitBlockRequest enum in rbuilder
• Update tests, workspace dependencies, and import grouping to reflect the change

Reviewed Changes

Copilot reviewed 10 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
crates/test-relay/src/validation_api_client.rs	Import external SubmitBlockRequest and drop the old local import
crates/test-relay/src/relay.rs	Use alloy_rpc_types_beacon SubmitBlockRequest and clean up imports
crates/test-relay/Cargo.toml	Add alloy-rpc-types-beacon as a workspace dependency
crates/rbuilder/src/provider/mod.rs	Consolidate RootHashError import into a single group
crates/rbuilder/src/mev_boost/submission.rs	Remove local SubmitBlockRequest enum and import external type
crates/rbuilder/src/mev_boost/sign_payload.rs	Switch to external SubmitBlockRequest in payload signing
crates/rbuilder/src/mev_boost/mod.rs	Update RelayClient and tests to use the external SubmitBlockRequest
crates/rbuilder/src/live_builder/block_output/bid_observer_multiplexer.rs	Switch to external SubmitBlockRequest import
crates/rbuilder/src/live_builder/block_output/bid_observer.rs	Switch to external SubmitBlockRequest import
crates/bid-scraper/src/main.rs	Reformat and group imports after migration

Comments suppressed due to low confidence (1)

crates/rbuilder/src/mev_boost/submission.rs:9

• The imported SubmitBlockRequest from alloy_rpc_types_beacon is not used in this module; consider removing it to clean up unused imports.

};

[ZanCorDX]

It's failing lint checks.
Have you checked if you didn't leave unused structs (ElectraSubmitBlockRequest/CapellaSubmitBlockRequest/DenebSubmitBlockRequest)?
Are the tests updated?

[varun-doshi]

Fixed lint and removed unused structs

make lint and make test run successfully