Optimize scenario tests: tests/scenarios/vectorized_backtests/

[MDUYN]

Problem

The vectorized backtest scenario tests in tests/scenarios/vectorized_backtests/ are too slow for CI (they cause Ubuntu runners to timeout). They are currently skipped via @unittest.skip.

Required changes

1. Reduce execution time — These tests run multiple vector backtests with parameter grids and multi-year date ranges. Reduce date ranges, shrink parameter grids, and ensure each test completes in under 30 seconds.

2. Use only offline test data from tests/resources/test_data/ — All data sources must reference CSV files located in tests/resources/test_data/ (or its subdirectories). Tests should not depend on data files scattered across tests/resources/data/ or tests/resources/market_data_sources_for_testing/. This ensures tests are self-contained, reproducible, and don't break when external data files are reorganized.

Affected files

• tests/scenarios/vectorized_backtests/test_run_vector_backtest.py
• tests/scenarios/vectorized_backtests/test_run_vector_backtests.py
• tests/scenarios/vectorized_backtests/test_use_checkpoints.py
• tests/scenarios/vectorized_backtests/test_use_backtest_storage_directory.py
• tests/scenarios/vectorized_backtests/test_with_show_progress.py
• tests/scenarios/vectorized_backtests/test_with_window_filter_function.py
• tests/scenarios/vectorized_backtests/test_with_final_filter_function.py
• tests/scenarios/vectorized_backtests/test_vector_backtest_fixes.py
• tests/scenarios/vectorized_backtests/test_metadata_preservation.py

Acceptance criteria

• All tests in this folder run in under 30 seconds each
• All tests use data exclusively from tests/resources/test_data/
• Remove the @unittest.skip decorator once optimized
• Tests pass on both macOS and Ubuntu CI runners