CI: avoid port-already-in-use errors
Should prevent the occasional CI failures e.g. https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=55705&view=ms.vss-test-web.build-test-results-tab&runId=2644226&resultId=178989&paneView=debug
cool https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=55858&view=logs&j=b516280a-8c75-541b-8ba0-ae13561718a7&t=88a240e0-0f0f-5fd5-6f10-d82e025ed5d5

I think this is why these were hard coded in the first place.

let's revert this CR.