Fix length check between kzg commitments and exist

[terencechain]

The exists array is always returned as [6]bool, with a fixed length of 6. Until this is made dynamically sized, we cannot assume it will always match the count of KZG commitments in the block body.

The key requirement is ensuring that the block body's KZG length doesn’t exceed the bounds of exists, meeting this constraint:

for i, commitment := range kzgCommitments {
	if !exists[i] {
		kzgHashes = append(kzgHashes, primitives.ConvertKzgCommitmentToVersionedHash(commitment))
	}
}

This PR modifies the check from an equality check to a greater-than check, so the body’s KZG count cannot be greater than the exists count.