ops-bedrock: Set batcher target tx size to 624 bytes

This is just a temporary remedy to (hopefully) make the devnet CIs pass.
624 bytes = 8 (~L2 per L1 blocks) * 78 bytes (empty block with just Deposited tx)
It's a delicate dance.

Propoer fix is to observe channel timeouts and sequencer window span so
that we can set an even larger target but still send txs quickly enough
when there's now tx volume.

ops-bedrock/docker-compose.yml

@@ -120,7 +120,7 @@ services:
       OP_BATCHER_L2_ETH_RPC: http://l2:8545
       OP_BATCHER_ROLLUP_RPC: http://op-node:8545
       OP_BATCHER_MAX_L1_TX_SIZE_BYTES: 120000
-      OP_BATCHER_TARGET_L1_TX_SIZE_BYTES: 1
+      OP_BATCHER_TARGET_L1_TX_SIZE_BYTES: 624
       OP_BATCHER_TARGET_NUM_FRAMES: 1
       OP_BATCHER_APPROX_COMPR_RATIO: 1.0
       OP_BATCHER_CHANNEL_TIMEOUT: 40