[pytest] Reverse PT001 and PT0023 defaults

[tjkuson]

Summary

This patch inverts the defaults for pytest-fixture-incorrect-parentheses-style (PT001) and pytest-incorrect-mark-parentheses-style (PT003) to prefer dropping superfluous parentheses.

Presently, Ruff defaults to adding superfluous parentheses on pytest mark and fixture decorators for documented purpose of consistency; for example,

 import pytest


-@pytest.mark.foo
+@pytest.mark.foo()
 def test_bar(): ...

This behaviour is counter to the official pytest recommendation and diverges from the flake8-pytest-style plugin as of version 2.0.0 (see m-burst/flake8-pytest-style#272). Seeing as either default satisfies the documented benefit of consistency across a codebase, it makes sense to change the behaviour to be consistent with pytest and the flake8 plugin as well.

This change is breaking, so is gated behind preview (at least under my understanding of Ruff versioning). The implementation of this gating feature is a bit hacky, but seemed to be the least disruptive solution without performing invasive surgery on the #[option()] macro.

Related to #8796.

Caveat

Whilst updating the documentation, I sought to reference the pytest recommendation to drop superfluous parentheses, but couldn't find any official instruction beyond it being a revealed preference within the pytest documentation code examples (as well as the linked issues from a core pytest developer). Thus, the wording of the preference is deliberately timid; it's to cohere with pytest rather than follow an explicit guidance.

Test Plan

cargo nextest run

I also ran

cargo run -p ruff -- check crates/ruff_linter/resources/test/fixtures/flake8_pytest_style/PT001.py --no-cache --diff --select PT001

and compared against it with --preview to verify that the default does change under preview (I also repeated this with echo '[tool.ruff]\npreview = true' > pyproject.toml to verify that it works with a configuration file).

[charliermarsh]

This makes sense to me -- thanks.