Remove blinded execution payload envelope

[gfukushima]

PR Description

Remove the blinded version of execution payload envelope following the change in the beacon api ethereum/beacon-APIs#624
We now use Eth-Blob-Data-Included to distinguish the request body of publishExecutionPayloadEnvelope

Fixed Issue(s)

Fixes #11044

Documentation

• I thought about documentation and added the doc-change-required label to this PR if updates are required.

Changelog

• I thought about adding a changelog entry, and added one if I deemed necessary.

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Note

Medium Risk
Changes the validator–beacon publish contract and Gloas gossip timing (payload blocked until sidecars are buildable), which can affect multi-node block production and blob availability.

Overview
Aligns Gloas execution payload publication with the updated beacon-APIs model: blinded envelopes and unblind-from-cache are removed, and publishExecutionPayloadEnvelope is split by Eth-Blob-Data-Included instead of Eth-Execution-Payload-Blinded.

Stateless (true): body is SignedExecutionPayloadEnvelopeContents (envelope plus blobs/KZG proofs). Stateful (false): body is SignedExecutionPayloadEnvelope; the node builds data column sidecars from cached getPayload data, with DataColumnSidecarCreationException when cache is missing or the payload root does not match (messages are returned to clients as rejections).

ExecutionPayloadPublisherGloas now runs broadcast validation in parallel with sidecar creation but gossip only after both succeed; if sidecars cannot be built but the block has no blob commitments, it still publishes the envelope with empty sidecars. Remote validator clients send the signed envelope directly with Eth-Blob-Data-Included: false (no auto-blind). OpenAPI drops blinded envelope schemas; produceBlockV4 treats include_payload as a required query parameter.

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[lucassaldanha]

Should we abort the entire publish if we can't reconstruct blobs for it? Looks like previously we would still accept the valid signed envelope, and now we won't.

[gfukushima]

looking into this, I think you're right, not having or being able to reconstruct should be reason enough to stop the publishing of the execution payload.