[test] Flaky test TestPasswordFromFile in plugin/storage/es/factory_test.go

https://github.com/jaegertracing/jaeger/actions/runs/6134973238/job/16648278200?pr=4742#step:7:4523

One strange thing I noticed in the output that the very last logged request to the server was with Basic Auth string looking like the first password, not the second password, as if the request with the second password was made but then someone again made a request with the old one. I wonder if the es.Client object can continue sending pings to the server if it's not Close-ed (which we don't do).