fix: fix blob sidecar index check (#7315)

Fix index check

Author: ensi321

packages/beacon-node/src/chain/validation/blobSidecar.ts

@@ -19,7 +19,7 @@ export async function validateGossipBlobSidecar(
   const blobSlot = blobSidecar.signedBlockHeader.message.slot;
 
   // [REJECT] The sidecar's index is consistent with `MAX_BLOBS_PER_BLOCK` -- i.e. `blob_sidecar.index < MAX_BLOBS_PER_BLOCK`.
-  if (blobSidecar.index < chain.config.MAX_BLOBS_PER_BLOCK) {
+  if (blobSidecar.index >= chain.config.MAX_BLOBS_PER_BLOCK) {
     throw new BlobSidecarGossipError(GossipAction.REJECT, {
       code: BlobSidecarErrorCode.INDEX_TOO_LARGE,
       blobIdx: blobSidecar.index,