feat: add workflow_dispatch trigger and upload artifact step for Kuvel build

Author: ChipWolf

.github/workflows/build.yml

@@ -8,6 +8,7 @@ on:
     paths-ignore:
       - "**.md"
       - "renovate.json"
+  workflow_dispatch:
 
 jobs:
   build:
@@ -27,3 +28,7 @@ jobs:
       - run: java -version
       - run: mvn --version
       - run: mvn -B package
+      - uses: actions/upload-artifact@v4
+        with:
+          name: Kuvel
+          path: target/Kuvel.jar