TypeScript RPC Client Test runs very slowly

[geoknee]

In our github action, the client runner waits 120 seconds or more for the rpc servers. but the logs show that they should be ready after about 10-15 seconds. so there's a long unexplained wait.

https://github.com/statechannels/go-nitro/actions/runs/6394026017/job/17354532231

I found various issues highlighting issues with localhost networking on github CI runners. So there may or may not be some known issues there:
https://github.com/cypress-io/github-action#wait-on-with-nodejs-18