miner: cap configured MaxBlobsPerBlock to protocol limit (#35295)

## Summary

- Only apply user-configured `MaxBlobsPerBlock` when it is strictly
below the protocol-defined maximum.
- Prevents the miner from building blocks that exceed the consensus blob
limit.

## Test plan

- [x] `go test -short ./miner/`

miner/worker.go

@@ -51,8 +51,8 @@ var (
 // Users can specify the maximum number of blobs per block if necessary.
 func (miner *Miner) maxBlobsPerBlock(time uint64) int {
 	maxBlobs := eip4844.MaxBlobsPerBlock(miner.chainConfig, time)
-	if miner.config.MaxBlobsPerBlock != 0 {
-		maxBlobs = miner.config.MaxBlobsPerBlock
+	if configured := miner.config.MaxBlobsPerBlock; configured != 0 && configured < maxBlobs {
+		maxBlobs = configured
 	}
 	return maxBlobs
 }