test: make the flush and logging output tests self-contained

[NoiceHax]

Description

tests/test_logging_output.py only checks the logger output, but its trackers kept the default CSV output on, so every run also appended a row to emissions.csv in the working directory. _persist_data calls the output handlers in a loop and the CSV one runs first, so once anything went wrong with that shared file the logger handler was never reached. flush() and stop() are wrapped in @suppress(Exception), so nothing was printed and the test failed later on a row count instead. The three trackers there now pass save_to_file=False, and tearDown checks that emissions.csv in the working directory was not touched.

tests/test_emissions_tracker_flush.py pointed every test at one fixed file name under tempfile.gettempdir(), so two tests could end up counting rows in the same file. Each test now gets its own temporary directory.

tests/conftest.py gets an autouse fixture that stops PeriodicScheduler timers a test left armed. The issue asks for that to stay a safety net, so it stays one.

One thing I left out on purpose: _persist_data could wrap each handler.out() call in try/except so a failing output method cannot drop the ones after it. That would have turned this silent failure into a warning, but it changes runtime behaviour, so I would rather do it separately if you want it.

Related Issue

#1371

Motivation and Context

These two test modules shared files with each other and with the rest of the suite, which is why they pass alone and fail in a full run. This removes the shared state. It does not touch library code.

How Has This Been Tested?

Ran the full suite five times on master and five times on this branch, on Windows 11 with Python 3.14. Both sets gave the same numbers: the three tests named in the issue passed every time, and the only failure was test_task_energy_with_live_update_interference, which already fails on master on this machine. So I could not reproduce the intermittent failure here and cannot claim a drop in the failure rate.

What I could reproduce is the coupling behind it. Replace emissions.csv in the repository root with something the CSV handler cannot write to, and all three tests in test_logging_output.py fail on master, even though none of them assert anything about CSV output. On this branch they pass.

Screenshots (if appropriate):

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• All new and existing tests passed. See the testing section above: one unrelated test fails on this machine on master as well.