test: increase limit again for network space overhead test

On certain platforms, updating V8 to 7.9 made the numbers a bit higher
than the current limit.

PR-URL: https://github.com/nodejs/node/pull/30020


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>