Update dpdk_pktgen_num_flows in default config for External IP.

PiperOrigin-RevId: 896548396

Author: abhishekshaw21

perfkitbenchmarker/configs/default_benchmark_config.yaml

@@ -55,7 +55,7 @@ dpdk_pktgen_multi_nic_small_pkt_loss_external_IP:
     dpdk_pktgen_max_lcores: 128
     assign_external_ip_all_nics: True
     ip_addresses: EXTERNAL
-    dpdk_pktgen_num_flows: 100
+    dpdk_pktgen_num_flows: 70
     dpdk_pktgen_tx_rx_lcores_list: ['[2:1]#[51:52];[1:2]#[51:52]','[51:52]#[2:1];[51:52]#[1:2]']
 
 dpdk_pktgen_multi_nic: