fix(cd): update artifact actions to use Gitea versions

.github/workflows/theme-cd.yaml

@@ -26,7 +26,7 @@ jobs:
       - name: Build
         run: pnpm build
       - name: Upload Artifacts
-        uses: actions/upload-artifact@v6
+        uses: christopherhx/gitea-upload-artifact@v4
         with:
           name: theme-package
           path: dist
@@ -39,7 +39,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - name: Download Artifacts
-        uses: actions/download-artifact@v6
+        uses: christopherhx/gitea-download-artifact@v4
         with:
           name: theme-package
           path: dist