test: remove duplicate test

`test/parallel/test-http-agent-no-wait.js` is basically a duplicate of
`test/parallel/test-http-client-close-with-default-agent.js`, remove it.

PR-URL: #44051
Reviewed-By: Paolo Insogna <[email protected]>
Reviewed-By: Feng Yu <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>
Reviewed-By: Antoine du Hamel <[email protected]>

Author: lpinca

test/parallel/test-http-agent-no-wait.js

@@ -20,4 +20,4 @@ server.listen(0, common.mustCall(() => {
 }));
 
 // This timer should never go off as the server will close the socket
-setTimeout(common.mustNotCall(), common.platformTimeout(10000)).unref();
+setTimeout(common.mustNotCall(), common.platformTimeout(1000)).unref();