include test execution time in the SHARED.UNITS results

[AdrickTench]

The /tmp/SHARED.UNITS test results should include the execution time for each test, so that information can be included as the time property for the testcase in the junit.xml we generate. See https://github.com/testmoapp/junitxml?tab=readme-ov-file#structure

[AdrickTench]

Time is being included now. Granted JUnit / allure may not be able to handle the microseconds precision, but we can dwim in into_junit.py if needed rather than lie about the times we record