- Changed all Python/pip commands to use `venv/bin/python -m` pattern instead of direct tool invocation or source activation
- package-tests.yml: pip, mypy, black, pytest now use `venv/bin/python -m`
- python-tests.yml: ruff, pip, pytest now use `venv/bin/python -m` or `venv/bin/pytest`
- staking-tests.yml: pytest now uses `venv/bin/pytest` instead of `python3 -m pytest`
- Added missing dependencies to workflow
Added --no-cache-dir to pip install commands for pip/setuptools/wheel, requirements file, and extra packages to reduce disk usage and ensure clean installations in CI environments.
Replaced manual venv creation and pip install commands with calls to scripts/ci/setup-python-venv.sh across all CI workflows. The script provides consistent venv setup with configurable options for requirements installation, copy mode, and extra packages.
- Changed from manual `python3 -m venv` + `pip install` to setup-python-venv.sh in all workflows
- Added --skip-requirements flag where workflows don't need requirements
