Merge #11867: Improve node network test
ee5efad6cf [tests] refactor node_network_limited (John Newbery)
b425131f5a [tests] remove redundant duplicate tests from node_network_limited (John Newbery)
2e02984591 [tests] node_network_limited - remove race condition (John Newbery)
dbfe294805 [tests] define NODE_NETWORK_LIMITED in test framework (John Newbery)
1285312048 [tests] fix flake8 warnings in node_network_limited.py (John Newbery)
Pull request description:
Fixes race condition in the node_network_limited test case introduced in #11740. Also tidies up the test and removes redundant duplicate tests.
Tree-SHA512: a5240fe35509d81a47c3d3b141a956378675926093e658d24be43027b20d3b5f0ba7c6017c8208487a1849d4fdfb911a361911d571423db7c50711250aba3011