I've created the resource and implemented it in some obvious places where comments pointed to flaky tests. There were certain tests I left alone as although they were marked flaky by inline comments, there were other decorators addressing this, for example certain tests that were marked as being flaky without the GIL are already marked with the @support.requires_gil_enabled decorator which I think makes more sense.

As with other resources, the use-case for decorating tests is just:

from test.support import requires_resource

@requires_resource('flaky')
def test_flaky_test():
...

With this set-up, in CI environments we can configure the CI to run flaky tests separately and to automatically retry failed flaky tests::

python -m test --use=flaky --rerun

• Issue: Add a new test resource to mark flaky tests #130474