Ruff lints the whole repo

[lpozo]

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Describe the bug

Currently, Ruff lints all the files in the repo, which can be inefficient.

To Reproduce
Steps to reproduce the behavior:

1. Open a PR and take a look at the Ruff check details.

Expected behavior
Lint only the modified Python files.

Additional context
Proposed update to file .github/workflows/linters.yaml

- name: Check code style
      run: |
        . venv/bin/activate
        if [ "$GITHUB_EVENT_NAME" = "pull_request" ]; then
          git fetch origin ${{ github.base_ref }}
          CHANGED_FILES=$(git diff --name-only origin/${{ github.base_ref }}...${{ github.sha }} -- '*.py')
        else
          CHANGED_FILES=$(git diff --name-only HEAD^ -- '*.py')
        fi
        if [ -n "$CHANGED_FILES" ]; then
          python -m ruff format --check $CHANGED_FILES
          python -m ruff check $CHANGED_FILES
        fi