fix(ci): downgrade upload-artifact from v4 to v3 for Gitea compatibility

- actions/upload-artifact@v4 not supported on Gitea
- Error: GHES (GitHub Enterprise Server) compatibility issue
- Using v3 which is compatible with Gitea Actions

.gitea/workflows/ci.yml

@@ -77,7 +77,7 @@ jobs:
         run: bash scripts/compile-all.sh
 
       - name: Upload binaries as artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v3
         with:
           name: nupst-binaries
           path: dist/binaries/*