chore(deps): update codecov/codecov-action action to v6

Author: renovate[bot]

.github/workflows/main.yml

@@ -37,7 +37,7 @@ jobs:
         run: bundle exec rspec
       - name: Upload coverage to Codecov
         if: ${{ strategy.job-index == 0 }} # only run codecov on first run
-        uses: codecov/codecov-action@v5.5.3
+        uses: codecov/codecov-action@v6.0.0
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           fail_ci_if_error: true