Fix #8000: pytest_fixture_setup hook doesn't run for session scoped fixture

[devjaikalyani]

# Fix: `pytest_fixture_setup` hook runs for session-scoped fixtures

## Summary
The `pytest_fixture_setup` hook was incorrectly skipping execution for session-scoped fixtures, even though it should run for all fixture scopes.

## Changes
- Updated `testing/test_scope.py` to test session-scoped fixture behavior.
- Adjusted `pyproject.toml` (details in PR).

## Testing
- Added test case for session-scoped fixture in `test_scope.py`.
- Verified `pytest_fixture_setup` now executes for session-scoped fixtures.

## Closes #8000