test: add simple runner test workflow

.forgejo/workflows/test-runner.yml

@@ -0,0 +1,15 @@
+name: Test Runner
+
+on:
+  push:
+    branches: [main, master]
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Hello
+        run: echo "Runner is working!"
+      - name: Docker check
+        run: docker version || echo "Docker not available"