in integration test build we need to make sure that only 1 instance builds at the same time and the other waits for it (this is in place done with mutex), and also that we don't start a new build until the previous test run completed. This needs to be somewhat resistant to cancellation,. where we can just abort the test project process.

this is problem that happens with acceptance integration tests and libraty acceptance tests, which in CI start at different times, so build is already done, and we probably re-build.