test: use common.PORT instead of hardcoded port number

PR-URL: https://github.com/nodejs/node/pull/39298
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/sequential/test-debugger-invalid-args.js

@@ -21,7 +21,7 @@ const { createServer } = require('net');
 
 // Launch w/ invalid host:port.
 {
-  const cli = startCLI(['localhost:914']);
+  const cli = startCLI([`localhost:${common.PORT}`]);
   cli.quit()
     .then((code) => {
       assert.match(