Context

When AllureFormatter.hide_excluded=True, Behave still reports step declarations for tag-excluded scenarios to the formatter. The listener dropped those scenarios without clearing its pending step queue, so their steps were later attached to the next included scenario.

This change clears pending steps when a scenario is dropped and adds an acceptance test that verifies a selected scenario contains only its own step.

Fixes #902

Checklist

• Sign Allure CLA
• Provide unit tests

Verification

• python -m pytest tests/allure_behave -q — 64 passed
• python -m ruff check allure-behave tests/allure_behave — all checks passed
• git diff --check HEAD^ HEAD