feat: overhaul CI

[rjwalters]

This PR completely restructures our CI workflows to make them more modular, efficient, and comprehensive. It replaces the previous monolithic approach with specialized workflows and introduces benchmarking capabilities.

Key Changes

• Modular Workflow Structure: Split the previous single build workflow into separate specialized workflows for Python and C++ testing, linting, and benchmarking
• Reusable Actions: Created shared setup actions for Python and C++ environments to avoid duplication
• Benchmarking Integration: Added comprehensive benchmark workflows using Google Benchmark for C++ and pytest-benchmark for Python
• Bencher.dev Integration: Configured workflows to submit benchmark results to Bencher.dev for performance tracking over time
• Code Quality: Improved linting workflows for both Python (using Ruff) and C++ (using clang-format)
• Dependency Management: Added Dependabot configuration to automatically track dependency updates
• Cleaner Organization: Renamed workflows for consistency (e.g., deploy_mettascope.yml → deploy-mettascope.yml)
• Removed Unused Files: Deleted obsolete test scripts and unnecessary trace files

Migration Notes

• The new benchmark framework replaces the previous custom benchmarking scripts
• Python benchmarks now use pytest-benchmark for consistency with the rest of our testing infrastructure
• Artifact naming and structure has been standardized across workflows
• Test paths and configurations have been updated to work with the modular approach

[daveey]

This made me very happy. Great work. I saw @berekuk left some comments. Feel free to merge when ready