v2.0.0 🌈 A new start

Summary

Converts the action from a composite to
javascript.

These changes will make it easier to bring in new features.

Changes

1. Download the ruff executable for the current platform from the GitHub
   releases
2. Add ruff to the PATH
3. Validate the downloaded ruff executable against its checksum
4. Cache ruff in the Tool
   Cache
   to speed up runs on self-hosted runners
5. Support semver ranges to define the ruff version to install

🚨 Breaking changes

Removes the changed-files input.

This input could previously be used to run ruff only on files changed in
a PR. The functionality was implemented by calling another action. This
repo should focus on providing a quick and easy way to use ruff in
GitHub Actions, not add more functionality on top of ruff.

The previous functionality can be replicated with:

- uses: actions/checkout@v4
- name: Get changed files
  id: changed-files
  uses: tj-actions/changed-files@v45
  with:
    files: |
      **.py
- name: Run ruff on changed files only 
  uses: astral-sh/ruff-action@v2
  with:
    src: ${{ steps.changed-files.outputs.all_changed_files }}