update coverage-check workflow to use 'npm run test:unit' for testing

Author: harshithad0703

.github/workflows/coverage-check.yml

@@ -21,7 +21,7 @@ jobs:
       - uses: ArtiomTr/jest-coverage-report-action@v2
         id: coverage
         with:
-          test-script: npm test
+          test-script: npm run test:unit
           threshold: 95
           working-directory: ./