Tests using port 5000 conflict with OS service on recent versions of macOS under some circumstances

[cardenaso11]

Context & versions

Present on recent master, 6e7b43a at minimum. I can reproduce on aarch64-darwin, macOS 14.1.2 23B92. cardano-node obtained from flake input, run as x86_64-darwin, via rosetta

Steps to reproduce

On a recent macOS device, if AirPlay receiving is enabled in System preferences, port 5000 will already be in use, and several hydra-cluster tests will fail sporadically. This might have gone unnoticed due to the nix shell for macOS not containing a cardano-node by default, causing lots of tests to skip running by default

Actual behavior

Tests sporadically fail due to not being able to open the port

Expected behavior

Tests should always run on macOS. Tests can change the port from 5000 (like starting hydra-cluster tests off at an offset like 5100, which is what I did as a temporary fix during development). In addition, it might be good to fail more explicitly if ports can't be opened for any reason

[cardenaso11]

Updating this with details

[cardenaso11]

I have a fix in the offline mode branch for just changing the port, going to add that here and see what I can do about making the port failures more clear