Update actions/upload-artifact action to v7 (#61)

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

Author: renovate[bot]

.github/workflows/build.yaml

@@ -20,7 +20,7 @@ jobs:
         run: gradle jar
 
       - name: Archive jar file
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: UltimateSpawn
           path: build/libs/UltimateSpawn.jar