chore: add threshold icons for coverage reporting in CI workflow

Author: c0reme

.github/workflows/ci-vitest.yml

@@ -23,3 +23,5 @@ jobs:
       - name: "Report Coverage"
         if: always()
         uses: davelosert/vitest-coverage-report-action@v2
+        with:
+          threshold-icons: "{0: '🔴', 80: '🟠', 90: '🟢'}"