Bump actions/upload-artifact from 5 to 6 in /.github/workflows

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/alpha.yml

@@ -113,7 +113,7 @@ jobs:
 
       - name: Upload signed msix
         if: success() && github.event_name != 'pull_request'
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: Snap.Hutao.Alpha-${{ steps.cake.outputs.version }}
           path: ${{ github.workspace }}/src/output/Snap.Hutao.Alpha-${{ steps.cake.outputs.version }}.msix