Create a new project and a default lock file using uv with:

uv init --project
uv lock

This sets up the pyproject.toml with a build backend.

To get github actions up and running we will reuse the installation of uv accross multiple jobs:

runs:
  using: composite
  steps:
    - name: Install uv
      uses: astral-sh/setup-uv@v3
      with:
        version: "0.4.19"