Include Dart version in coverage upload name

Author: joechung2008

.github/workflows/ci.yml

@@ -38,6 +38,6 @@ jobs:
       - name: Upload coverage
         uses: actions/upload-artifact@v4
         with:
-          name: coverage-html-${{ matrix.package }}
+          name: coverage-lcov-${{ matrix.package }}-${{ matrix.dart-version }}
           path: packages/${{ matrix.package }}/coverage/
           if-no-files-found: ignore