feat: migrate python-crawlee-parsel to pyproject.toml + uv

[vdusek]

Summary

• Replace requirements.txt + pip with pyproject.toml + uv for the python-crawlee-parsel template
• Add ruff, ty, pytest, and pytest-asyncio as dev dependencies
• Update Dockerfile to use uv sync --frozen with lockfile for reproducible builds
• Update test harness to support both pyproject.toml and requirements.txt templates
• Add astral-sh/setup-uv@v6 to CI workflow

Test plan

• cd templates/python-crawlee-parsel && uv sync installs all deps
• uv run ruff check my_actor/ passes
• uv run ty check passes
• Docker build succeeds
• CI passes for all Python templates (both pyproject.toml and requirements.txt)

🤖 Generated with Claude Code