Update actions/upload-artifact action to v7

Author: renovate[bot]

.github/workflows/build.yml

@@ -18,7 +18,7 @@ jobs:
       - name: "Clean Build"
         run: "./gradlew clean build"
       - name : "Archive Artifacts"
-        uses : "actions/upload-artifact@v3"
+        uses : "actions/upload-artifact@v7"
         with :
           name : "PRTree-SNAPSHOT"
           path : "build/libs/*-SNAPSHOT.jar"