[flake8-pytest-style] PT001/PT023 fix makes syntax error on parenthesized decorator - #18782

Fixes #18771

Summary

1. PT001 – @pytest.fixture parentheses style

• Handles alias-imported fixtures and decorators wrapped in an outer pair of parentheses (e.g. @(pytest.fixture())).
• Ensures the rule honours the lint.flake8-pytest-style.fixture-parentheses setting for every variant.
• Updates reference tests (PT001.py) and snapshots.

2. PT023 – @pytest.mark.<marker> parentheses style

• Extends the checker so it also flags/removes superfluous parentheses when the mark is applied to classes, nested classes, or is itself wrapped in outer parentheses.
• Keeps behaviour consistent with lint.flake8-pytest-style.mark-parentheses.
• Adds/updates fixture file (PT023.py) and snapshots.

Test Plan

1. Unit / snapshot tests

• cargo nextest run (or cargo test) — all suites pass.
• Updated PT001 and PT023 snapshots reviewed and accepted via cargo insta review.

2. Manual smoke test

• Ran ruff check on a sample project with mixed fixture/mark styles to confirm that:
• Unnecessary parentheses are now flagged/auto-fixed in every location.
• Legitimate calls with arguments remain unaffected.