CORE-2212: test: do not start seastar for --gtest_list_tests

[dotnwat]

    /*
     * if the test is being passed --gtest_list_tests then do not start Seastar.
     * this is an important optimization for using `gtest_discover_tests`
     * because every test exectuable is queried in parallel, and the result is
     * that listing would timeout or seastar would exhaust some kind of resource
     * like aio-max-nr.
     */

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v23.3.x
• v23.2.x

Release Notes

• none

[vbotbuildovich]

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/47620#018ec8e2-2409-483d-913d-4b14b4f353c2