[tests] remove redundant duplicate tests from node_network_limited

Summary:
Partial backport of core PR11867 (commit b425131)

Depends on D2368

Test Plan:

./test/functional/test_runner.py node_network_limited.py

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: teamcity, schancel

Differential Revision: https://reviews.bitcoinabc.org/D2369