Retry tests 3 times on CI only (when CI
environment variable is present). In development run tests only once for easier development.
How to retry failed tests (flaky tests)? https://knapsackpro.com/faq/question/how-to-retry-failed-tests-flaky-tests
Fix intermittently failing CI builds due to flaky tests in RSpec https://docs.knapsackpro.com/2021/fix-intermittently-failing-ci-builds-flaky-tests-rspec