Sepolia op-node cannot get blobs from Caplin

**Bug Description**
I'm seeing this error from a Base Sepolia node connected to a Caplin beaon
```
Oct 15 05:03:47 juju-8111ad-0 op-node[622705]: t=2025-10-15T05:03:47+0000 lvl=warn msg="Deriver system is resetting" err="derivation failed: reset: failed to fetch blobs: failed to get blob sidecars for L1BlockRef 0x581bc6ad3f156c04c77a6772cb04cec0ffd92fb909d772d1b1af638f06568e62:9408578: failed to fetch blob sidecars for slot 8724483: failed request with status 404: {\"code\":404,\"message\":\"blobs are not supported after fulu fork\"}\n: not found"
```

**Steps to Reproduce**
1. Run a Sepolia op-node
2. Set `--l1-beacon` to use a Erigon Caplin beacon node

**Expected behavior**
The node should be able to fetch blobs and sync

**Environment Information:**
Running on Ubuntu 22.04
op-node version v1.14.1-c1081e3a-1759886077
Erigon version 3.2.0-3418e071

**Configurations:**
op-node
```
--l2.jwt-secret=/home/op/jwtsecret --l2=ws://localhost:8551
--rpc.addr=0.0.0.0 --metrics.enabled --metrics.addr=0.0.0.0 --metrics.port=7300
--network=base-sepolia --p2p.bootnodes=enr:-J64QBwRIWAco7lv6jImSOjPU_W266lHXzpAS5YOh7WmgTyBZkgLgOwo_mxKJq3wz2XRbsoBItbv1dCyjIoNq67mFguGAYrTxM42gmlkgnY0gmlwhBLSsHKHb3BzdGFja4S0lAUAiXNlY3AyNTZrMaEDmoWSi8hcsRpQf2eJsNUx-sqv6fH4btmo2HsAzZFAKnKDdGNwgiQGg3VkcIIkBg,enr:-J64QFa3qMsONLGphfjEkeYyF6Jkil_jCuJmm7_a42ckZeUQGLVzrzstZNb1dgBp1GGx9bzImq5VxJLP-BaptZThGiWGAYrTytOvgmlkgnY0gmlwhGsV-zeHb3BzdGFja4S0lAUAiXNlY3AyNTZrMaEDahfSECTIS_cXyZ8IyNf4leANlZnrsMEWTkEYxf4GMCmDdGNwgiQGg3VkcIIkBg
--l1="http://192.168.110.67:8545" --l1.beacon="http://192.168.111.205:5053" --rpc.port=9545
--log.level=info --rollup.load-protocol-versions=true --rollup.halt=major --l1.trustrpc=true
--l1.rpckind=erigon --p2p.listen.tcp=9333
```

Erigon
```
--chain=sepolia --prune.mode=archive --caplin.states-archive --caplin.blocks-archive --caplin.blobs-archive --caplin.blobs-no-pruning --http --ws --http.addr=0.0.0.0 --http.port=8545 --http.vhosts=* --http.api=eth,net,web3,debug,trace,erigon --metrics --metrics.addr=0.0.0.0 --beacon.api=beacon,builder,config,debug,events,node,validator,lighthouse --beacon.api.addr=0.0.0.0
```

**Logs:**

[op-node.log](https://github.com/user-attachments/files/22920521/op-node.log)

Reproduce the failure with a Sepolia op-node using the reported --l1.beacon endpoint and Erigon Caplin 3.2.0 configuration. Start from the logged blob-sidecar request for slot 8724483 and compare the response with the expected blob-fetch behavior; done means the op-node can fetch the required blobs and sync without resetting.

Written by the indexing model from the issue text.