fix allocation size of proofs in ComputeCellsAndProofsFromStructured (#15809)

* fix allocation size of proofs in ComputeCellsAndProofsFromStructured

the preallocated slice for KZG Proofs was 48x bigger than it needed to
be.

* changelog

---------

Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>
Co-authored-by: james-prysm <90280386+james-prysm@users.noreply.github.com>

beacon-chain/core/peerdas/reconstruction.go

@@ -257,7 +257,7 @@ func ComputeCellsAndProofsFromStructured(blobsAndProofs []*pb.BlobAndProofV2) ([
 			return nil, errors.Wrap(err, "compute cells")
 		}
 
-		kzgProofs := make([]kzg.Proof, 0, numberOfColumns*kzg.BytesPerProof)
+		kzgProofs := make([]kzg.Proof, 0, numberOfColumns)
 		for _, kzgProofBytes := range blobAndProof.KzgProofs {
 			if len(kzgProofBytes) != kzg.BytesPerProof {
 				return nil, errors.New("wrong KZG proof size - should never happen")

beacon-chain/core/peerdas/reconstruction_test.go

@@ -441,6 +441,7 @@ func TestComputeCellsAndProofsFromStructured(t *testing.T) {
 		for i := range blobCount {
 			require.Equal(t, len(expectedCellsAndProofs[i].Cells), len(actualCellsAndProofs[i].Cells))
 			require.Equal(t, len(expectedCellsAndProofs[i].Proofs), len(actualCellsAndProofs[i].Proofs))
+			require.Equal(t, len(expectedCellsAndProofs[i].Proofs), cap(actualCellsAndProofs[i].Proofs))
 
 			// Compare cells
 			for j, expectedCell := range expectedCellsAndProofs[i].Cells {

changelog/marcopolo_push-nxynxywxtlpo.md

@@ -0,0 +1,2 @@
+### Ignored
+- Fix (unreleased) bug where the preallocated slice for KZG Proofs was 48x bigger than it needed to be.