chore(deps): update actions/upload-artifact action to v4 (#5)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
         with:
           dotnet-version: 9.0.x
       - run: dotnet pack src/ZaString -c Release -o ./artifacts
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
           name: nuget
           path: artifacts/*.nupkg