Fix security issue in opencv dependency, rework project structure and workflows, fix overflow

[merschformann]

Description

Updated GitHub Actions workflows for building and publishing, migrated to pyproject.toml from setup.py, addressed security issue in upstream opencv dependency and fixed an overflow that may have occurred in color distance calculation.

Changes

• Updated build workflow to use actions/checkout@v4 and actions/setup-python@v5.
• Replaced flake8 with ruff for linting.
• Reworked publish workflow with version bumping and release creation.
• Introduced pyproject.toml for project metadata and build configuration.
• Removed requirements.txt and setup.py in favor of pyproject.toml.
• Added brickmos/__about__.py to manage project version.
• Fixes and overflow that may have occurred in color distance calculation.