fix: Run coverage only on Node.js 20.x to avoid v8 coverage incompatibility with Node 18

Author: karanyede

.github/workflows/ci.yml

@@ -37,10 +37,12 @@ jobs:
       - name: Run unit tests
         run: npm test
 
-      - name: Run tests with coverage
+      - name: Run tests with coverage (Node 20.x only)
+        if: matrix.node-version == '20.x'
         run: npm run test:coverage
 
       - name: Upload coverage to Codecov
+        if: matrix.node-version == '20.x'
         uses: codecov/codecov-action@v3
         with:
           files: ./coverage/coverage-final.json