*: remove legacy un-versioned attestations

[KaloyanTanev]

Pre-electra we have used attestation objects, but post-electra we have moved to versioned attestations. Remove the unused logic now.

category: misc
ticket: none

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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[Copilot]

Pull request overview

This PR removes the legacy, un-versioned attestation wrapper and updates tracker/proto paths to operate exclusively on core.VersionedAttestation, aligning the core signing/tracking pipeline with the post-Electra “versioned attestation” model.

Changes:

• Remove the legacy core.Attestation signed-data wrapper (and related SSZ/JSON helpers) in favor of core.VersionedAttestation.
• Update inclusion tracking and tests to submit/version-hash attestations via the versioned wrapper.
• Simplify proto unmarshalling for attester partial signatures to decode only VersionedAttestation.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
core/tracker/inclusion.go	Drops legacy attestation handling during submission; hashes only versioned attestations.
core/tracker/inclusion_internal_test.go	Migrates inclusion tests to construct/submit versioned attestations.
core/signeddata.go	Removes legacy Attestation type and helpers; keeps versioned attestation as the signed-data representation.
core/signeddata_test.go	Removes tests specific to the deleted legacy Attestation type.
core/sigagg/sigagg.go	Minor clarification/cleanup in the validator-index selection logic for attestations.
core/proto.go	Removes legacy attestation decoding path; only unmarshals VersionedAttestation for attester duties.
core/eth2signeddata.go	Removes legacy attestation Eth2SignedData implementation; relies on versioned attestation instead.

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[codecov]

Codecov Report

❌ Patch coverage is 46.66667% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 57.87%. Comparing base (ca99f9f) to head (7fe4bdd).

Files with missing lines	Patch %	Lines
core/tracker/inclusion.go	25.00%	3 Missing and 3 partials ⚠️
core/proto.go	50.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4621      +/-   ##
==========================================
+ Coverage   57.73%   57.87%   +0.13%     
==========================================
  Files         246      246              
  Lines       33993    33941      -52     
==========================================
+ Hits        19625    19642      +17     
+ Misses      11905    11836      -69     
  Partials     2463     2463              

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[OisinKyne]

Some part of me worries i'll regret us removing the ability for charon to run on older forks, but i don't think this is the first occasion of us doing that so ticking approve

[KaloyanTanev]

@OisinKyne This one doesn't prevent us running older forks! The difference is that previously we have used:

// Attestation is the Ethereum 2 attestation structure.
type Attestation struct {
	AggregationBits bitfield.Bitlist `dynssz-max:"MAX_VALIDATORS_PER_COMMITTEE" ssz-max:"2048"`
	Data            *AttestationData
	Signature       BLSSignature `ssz-size:"96"`
}

While now we do use

// VersionedAttestation contains a versioned attestation.
type VersionedAttestation struct {
	Version        DataVersion
	ValidatorIndex *phase0.ValidatorIndex
	Phase0         *phase0.Attestation
	Altair         *phase0.Attestation
	Bellatrix      *phase0.Attestation
	Capella        *phase0.Attestation
	Deneb          *phase0.Attestation
	Electra        *electra.Attestation
	Fulu           *electra.Attestation
}

Which has either the phase0 attestation from the first one, or the electra one.