chore: Lower throughput on public (#17752)

Author: PhilWindle

spartan/environments/staging-public.env

@@ -23,7 +23,7 @@ PROVER_FAILED_PROOF_STORE=gs://aztec-develop/staging-public/failed-proofs
 TEST_ACCOUNTS=false
 SPONSORED_FPC=true
 SEQ_MIN_TX_PER_BLOCK=0
-SEQ_MAX_TX_PER_BLOCK=8
+SEQ_MAX_TX_PER_BLOCK=1
 
 VALIDATOR_REPLICAS=5
 VALIDATORS_PER_NODE=16