ops: pass through start block height to dtl

Without this explicitly configured, the `ops` package
would hang on my machine. It was incorrectly using a start height
greater than the size of the L1 chain

.changeset/rotten-hornets-call.md

+---
+'@eth-optimism/integration-tests': patch
+---
+
+Pass through starting block height to dtl

ops/envs/dtl.env

@@ -8,6 +8,7 @@ DATA_TRANSPORT_LAYER__POLLING_INTERVAL=100
 DATA_TRANSPORT_LAYER__LOGS_PER_POLLING_INTERVAL=2000
 DATA_TRANSPORT_LAYER__DANGEROUSLY_CATCH_ALL_ERRORS=true
 DATA_TRANSPORT_LAYER__SERVER_HOSTNAME=0.0.0.0
+DATA_TRANSPORT_LAYER__L1_START_HEIGHT=1
 
 DATA_TRANSPORT_LAYER__ADDRESS_MANAGER=
 DATA_TRANSPORT_LAYER__L1_RPC_ENDPOINT=