Running dotnet test on integration tests will run Build (the method) on both #15453
Description
When running dotnet test S:\p\vstest\test\Microsoft.TestPlatform.Acceptance.IntegrationTests\Microsoft.TestPlatform.Acceptance.IntegrationTests.csproj --filter RunTestsShouldThrowOnStackOverflowException
the projects don't know that they are each running an instance, and will both run the preparation for the run (implmented in assemblyInitialize via Build method0. This will prepare the environment twice for the tests.
Documenting here, to see if we can move to 1 project with 1 tfm to avoid this issue, or if some projects (like for translation layer tests) are needed to build as well, and we should write some muxers that will ensure we setup only once, and we don't re-setup for subsequent tests (in the same dotnet test invocation) even when running in series.