chore(deps): update actions/upload-artifact action to v6 (#233)

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

Author: renovate[bot]

.github/workflows/gradle.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Build with Gradle
         run: ./gradlew build
       - name: Upload a Build Artifact
-        uses: actions/upload-artifact@v5.0.0
+        uses: actions/upload-artifact@v6.0.0
         with:
           # Artifact name
           name: PistonQueue