The arcade-services internal CI build should not run unit tests

[premun]

We usually don't run tests in the main build again after they've been run in PR so I think we shouldn't run them in arcade-services-official-ci neither.

• They add 10+ minutes
• These tests fail every now and then
• The reason these fail is because of the CodeCoverage tool loading some settings (this should be fixed too regardless)

Release Note Description

Only run tests during PR builds

[missymessa]

Add to ProdCon epic.

[premun]

@dkurepa maybe we could do this? Another flakey failure prevented a package to be produced: https://dev.azure.com/dnceng/internal/_build/results?buildId=2169463&view=logs&j=a5c6a902-5556-5a70-4b67-7f49bfe8ebe3&t=30522ad2-fb1e-5545-250b-00b27148e543

[dkurepa]

I added it to the epic, looks like a good change. We should also make sure that github is configured so you have to run builds against the latest main

[premun]

Do we want that though? I am not so much in favour of that and we usually don't do that in other repositories

[dkurepa]

I think we do. Let's say we had two PR's that both passed the public PR validation over night. Merging one could affect the other in some way, I think we'd want to run validation on the second one again, just to be sure

[premun]

I understand the issue, I just don't think it happens so often that it would justify the hassle and time spent waiting rerunning PR builds

[dkurepa]

PR: #2619

[dkurepa]

The PR has been merged. We will only run tests during PR builds now. This should reduce the noise we're getting in main builds because of flaky tests