Please make it possible to override the rerun count globally

[mgorny]

Consider the following sample:

import pytest


@pytest.mark.flaky
def test_foo():
    assert False


@pytest.mark.flaky(reruns=3)
def test_bar():
    assert False

This causes the tests to be rerun exactly once and 3 times, independently of --reruns=... parameter on the CLI. I would find it really helpful to be able to override the upstream defaults somehow via the command-line, as our downstream workflows often suffer from much more flakiness than the pristine upstream CI.

[mgorny]

Oh, and I'd be happy to make a pull request, but I'd like to hear what you think and how you'd like it implemented first.

The most logical approach to me would be that reruns in config sets the default, markers override that, and CLI overrides everything. However, that's a potentially breaking change, so if you prefer, I can add a separate CLI option for that.

[icemac]

Currently we have the priority documented here: https://github.com/pytest-dev/pytest-rerunfailures?tab=readme-ov-file#priority

Changings in the list would require different usage patterns for at least some users who are used to the current priorites, so I see only a new override commandline option as a way to fulfill your change request.

PR is welcome.