Broken config if BPO is scheduled to genesis.

[barnabasbusa]

Describe the bug
Nimbus currently cannot handle BPO to be scheduled to genesis.

To Reproduce

participants:
  - cl_type: lighthouse
    cl_image: sigp/lighthouse:v8.0.1
    el_type: geth
    el_image: ethereum/client-go:v1.16.7
  - cl_type: nimbus
    cl_image: statusim/nimbus-eth2:multiarch-v25.11.1
    el_type: geth
    el_image: ethereum/client-go:v1.16.7

network_params:
  fulu_fork_epoch: 0
  bpo_1_epoch: 0

/eth/v1/config/spec beacon api should return

    "BLOB_SCHEDULE": [
      {
        "EPOCH": "0",
        "MAX_BLOBS_PER_BLOCK": "15"
      }
    ],

But instead, it returns:

    "BLOB_SCHEDULE": []