Vector Search Throughput regressed.

We were getting thput = 61 with 7.6.0-2005
https://perf.jenkins.couchbase.com/job/atlas-multiclient/45/ 

But with 7.6.0-2054 thput = 21
https://perf.jenkins.couchbase.com/job/atlas-multiclient/46/console 
Logs: 

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-atlas-multiclient-46/172.23.99.211.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-atlas-multiclient-46/172.23.99.39.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-atlas-multiclient-46/172.23.99.40.zip

Looking into cbmonitor graph comparison:

http://cbmonitor.sc.couchbase.com/reports/html/?snapshot=fts_760-2054_run_test_70dd&&label=7.6.0-2054&snapshot=fts_760-2005_run_test_b760&label=7.6.0-2005 
in 2054 build:

1. Cpu utilization dropped
   

2. total_bytes_query_results increased

1. total_queries_slow I am not sure what this tell us but.. ( It seems to be dropped to much lower constant value)