test: move test-net-connect-econnrefused from pummel to sequential

test-net-connect-econnrefused esems to run quickly on all platforms and
does not appear to need to be in the pummel directory. Move to
sequential.

PR-URL: https://github.com/nodejs/node/pull/38462


Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>