ci: update test runner for vitest (#186)

.github/workflows/test.yaml

@@ -16,10 +16,11 @@ jobs:
           node-version: ${{ matrix.node-version }}
           cache: npm
       - run: npm ci
+      - run: npm i -D @vitest/coverage-v8
       - run: npm run lint
-      - run: npm test -- --coverage --coverageDirectory=coverage/results-${{ matrix.node-version }}
+      - run: npm test -- --coverage
       - uses: actions/upload-artifact@v3
         with:
           name: vitest-results-${{ matrix.node-version }}
-          path: coverage/results-${{ matrix.node-version }}/*.xml
+          path: coverage/*
         if: ${{ always() }}