Migrate to pyproject.toml (PEP 517/518)

[Copilot]

Migrates project from legacy setup.py + separate requirements files to modern pyproject.toml configuration.

Changes

• Added pyproject.toml

  • Build system: setuptools backend
  • Dependencies consolidated from requirements.txt
  • Dev dependencies as optional extras: pip install .[dev]
  • Entry points for certbot plugin
  • Automatic package discovery

• Removed legacy files

  • setup.py
  • requirements.txt
  • requirements-dev.txt

• Updated CI workflows

  • Changed pip install -r requirements-dev.txt → pip install .[dev] in:
    • unit-tests.yml
    • linting.yml
    • formatting_check.yml

• Updated build configs

  • snap/snapcraft.yaml: Removed python-requirements (plugin auto-detects pyproject.toml)
  • Makefile: Package pyproject.toml instead of setup.py

Usage

# Install package
pip install .

# Install with dev dependencies
pip install .[dev]

# Build distributions
python -m build

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• publicsuffix.org
  • Triggering command: /usr/bin/python python -m unittest tests/__init__.py tests/cert_client.py (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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