fix(ci): remove broken coverage-badge step (#106)

* fix(ci): add Codecov token and branch coverage to test workflow

- Add token: ${{ secrets.CODECOV_TOKEN }} to codecov-action step
- Add --cov-branch to pytest for branch coverage reporting

* chore: add coverage artifacts to gitignore and Codecov badge to README

- Add .coverage, coverage.xml, coverage-badge.svg to .gitignore
- Add Codecov coverage badge to README badge row

* fix(ci): remove broken coverage-badge step, use Codecov badge instead

coverage-badge depends on pkg_resources which was removed from
setuptools>=71. Codecov already provides a hosted badge so this
step is redundant.

Author: billy-enrizky

.github/workflows/test.yml

@@ -76,12 +76,6 @@ jobs:
           fail_ci_if_error: false
           verbose: true
 
-      - name: Generate coverage badge
-        if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.12' && github.ref == 'refs/heads/main'
-        uses: tj-actions/coverage-badge-py@v2
-        with:
-          output: coverage-badge.svg
-
       - name: Add coverage PR comment
         if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.12' && github.event_name == 'pull_request'
         uses: MishaKav/pytest-coverage-comment@main